»f-e'---"^-« 


^: 


JkJ^ 


m9w 


^:j'm^ 


■LIBRARY 

UNIVERSITY  OF 
CALIFORNIA 
SANTA    CRUZ 


/^  -^ StmHc,,^  ^ 


Digitized  by  the  Internet  Archive 

in  2007  with  funding  from 

IVIicrosoft  Corporation 


http://www.archive.org/details/doctrineofdescenOOschmrich 


THE 

DOCTRINE  OF  DESCENT 
AND   DARWINISM 


BY 

OSCAR  SfflMIDT 

PROFESSOR   IN    THE    UNIVERSITY   OF   STRASBURG 
WITH   TWENTY-SIX   WOODCUTS 


NEW     YORK 

D.    APPLETON    AND     COMPANY 

1896 


Authorized  Edition. 


6^h 

S35 


PREFACE. 


The  imiiortant  chapter  which  closes  this  work  was 
included  in  a  public  lecture  which  I  delivered  at  the 
meeting  of  Naturalists  and  Physicians  held  this  year  at 
Wiesbaden  ;  my  purpose  being,  as  I  am  willing  to  con- 
fess, to  ascertain,  by  experience,  whether  on  this  signifi- 
cant subject  I  had  struck  the  right  note  to  suit  a  circle 
of  hearers  and  readers  not  hampered  by  prejudice. 

After  the  reception  given  to  this  fragment,  which  I 
also  issued  in  a  separate  pamphlet,  under  the  title  of 
"  The  Doctrine  of  Descent,  in  its  application  to  Man  " 
(Die  Anwendung  der  Descendenzlehre  auf  den  Mens- 
chen),  I  venture  to  hope  that  the  whole  may  find  a 
welcome. 

With  the  exception  of  the  Ecclesiastico-political 
question,  no  sphere  of  thought  agitates  the  educated 
classes  of  our  day  so  profoundly  as  the  doctrine  of  de- 
scent.  On  both  subjects  the  cry  is,  "Avow  your  colours!" 


^1  PREFACE. 

We  have,  therefore,  endeavoured  to  define  our  standpoint 
sharply  in  the  introduction,  and  to  preserve  it  rigidly 
throughout  the  work.  This  is,  indeed,  a  case  in  which, 
as  Theodor  Fechner  has  recently  said,  a  definite  deci- 
sion has  to  be  made  between  two  fundamental  alter- 
natives. May  our  exposition  afford  a  lucid  testimony 
to  this  dictum  of  one  of  the  patriarchs  of  the  philo- 
sophical view  of  nature. 


Stbasburg,  October  i8ih,  1873. 

Oscar  Schmidt. 


CONTENTS. 


I. 

PAUR 

1  VTRODucTioN— Summary  of  the  Results  of  Linguistic  Inquiry 
—Positive  Knowledge  preliminary  to  the  Doctrine  of 
Descent— Belief  in  Miracle— The  Limits  of  the  Lsvesti- 
GATioN  OF  Nature       ••.,,,...        r 


II. 

The  Animal  World  in  its  Present  State    .       .       •       .       .      24 

in. 

The  Phenomena  of  Reproduction  in  the  Animal  World.       .      39 

IV 
The  Animal  World  in  its  Historical  and  Pal.^ontological 
Development        ••••• 60 

V. 

The  Standpoint  of  the  Miraculous,  and  the  Investigation 
of  Nature— Creation  or  Natural  Development — Linnaeus 
—Cuvier—Agassiz— Examination  of  the  Idea  of  Species  ,      8a 

VI. 

Natural  Philosophy— Goethe— Predestined  Transformation 
according  to  Richard  Owen— Lamarck T04 


viii  CONTENTS. 


VII. 

PAGE 

Lyell  and  Modern  Geology— Darwin's  Theory  of  Selection 
—^  Beginning  of  Life 127 

VIII. 
Heredity— Reversion— Variability— Adaptation —Results    of 
Use  and  Disuse  of  Organs— Differentiation  leading  to 
Perfection 165 


IX. 

The  Development  of  the  Individual  (Ontogenesis)  is  a  Re- 
petition of  the  Historical  Development  of  the  Family 
(Phylogenesis) 195 

X. 

The  Geographical  Distribution  of  Animals  in  the  light  of 

the  Doctrine  of  Derivation 222 

XI. 

The  Pedigree  of  Vertebrate  Animals 248 

XII. 

Man 282 

References  and  Quotations 311 


LIST  OF   ILLUSTRATIONS. 


Fixi                                                                                                    •  PAGE 

1.  Legs  of  Bird  and  Chick    ....               ...  9 

2.  Mkdusa,  Tiaropsis  Diadema "SI 

3.  Stauridium.    Medusa,  Cladonema  Radiatum      ...  43 

4.  Spermatozoa 45 

5.  Section  of  Larva  of  Calcareous  Sponge     ....  51 

6.  Embryo  of  Hydrophilus  Piceus 53 

7.  Sessile  Stage  of  Crixo:d 56 

8.  Larva  of  Crayfish 56 

9.  Graptolites 69 

10.  Trilobites  remipes 70 

11.  Pal^oniscus 72 

12.  Larva  of  Echinoderm 197 

13.  Larva  of  Sea-Snail 200 

14.  Stauridium.    Cladonema 203 

15.  Hydractinea  carnea 204 

16.  Larva  of  Parasitic  Crustacea 207 

17.  AXOLOTL 208 

18.  Amblystoma 209 

rg.    Ammonites  Humphresianus 214 

20.  Ancyloceras 216 

21.  Section  of  Larva  of  Calcareous  Sponge     ....  217 

22.  Larva  of  Lancelet 251 

23.  Larva  of  Ascidian 253 

24.  Full-grown  Ascidian 255 

85.    Impression  of  Tail  of  Arch.eopteryx 266 

26.    Skeletons  of  Feet  :  Anchitherium.  Hipparion,  Horse  274 


THE   DOCTRINE  OF   DESCENT 
AND    DARWINISM. 


I. 

rntroduction— Summary  of  the  Results  of  Linguistic  Inquiry — Positive  Know- 
ledge preliminary  to  the  Doctrine  of  Descent— Belief  in  Miracle — The 
Limits  of  the  Investigation  of  Nature. 

A  CRAVING  to  understand  existence  pervades  mankfnd, 
and  the  life  of  every  self-conscious  individual.  Every 
system  of  philosophy  has  endeavoured  to  penetrate  into 
the  nature  of  things,  and  has  originated  in  the  attempt 
to  apprehend  the  coherency  of  those  great  series  of 
material  and  spiritual  phenomena,  of  which  man  flat- 
ters himself  that  he  is  the  centre  or  the  end. 

Some  quiet  themselves  by  emphasizing  the  contrast 
between  mind  and  body,  idea  and  phenomenon ;  others, 
by  the  catchword  of  identity ;  some  have  deemed  them- 
selves and  the  world  in  the  most  beautiful  harmony ; 
others,  from  the  times  of  the  Buddhists,  in  the  6th  cen- 
tury B.C.,  to  the  eccentric  saints  of  the  present  day,  the 
followers  and  reformers  of  Schopenhauer's  system,  re- 
gard the  world  as  a  mere  accumulation  of  discomfort 
and  conflict,  from    which  the   sage   mny  escape  by  a 


2  THE  DOCTRINE  OF  DESCENT. 

complete  withdrawal  into  himself,  and  a  return,  by  the 
force  of  an  iron  will,  to  an  absence  of  needs  and  to 
nothingness. 

In  all  these  endeavours  to  be  reconciled  and  contented 
with  the  world,  the  consciousness  of  man  has  made  no 
very  important  progress.  Marvellous  as  are  the  attain- 
ments of  our  generation,  whether  in  the  domain  of 
individual  sciences,  or  in  the  sphere  of  commerce  and 
industry,  it  is  scarcely  less  wonderful  how  little  certain 
or  advanced  is  the  opinion  of  the  multitude  on  general 
questions.  Even  now,  as  much  as  in  the  days  of 
Aristophanes,  the  multitude,  and  likewise  many  men 
of  "culture,"  allow  themselves  to  be  imposed  upon 
by  empty  jargon.  We  no  longer  burn  witches,  but 
verdicts  of  heresy  still  abound.  As  the  basis  of  sci- 
entific medicine,  our  experimental  physiology  enjoys 
unexampled  encouragement,  and  a  general  instinctive 
recognition  unparalleled  in  former  times ;  but  these 
do  not  prevent  the  door  from  remaining  open,  in  all 
classes  of  society,  to  the  most  audacious  quackery. 

We  have  only  to  look  round  at  the  spiritualists  and 
summoners  of  souls,  who  now  form  special  sects  and 
societies ;  at  the  advocates  of  cures  by  sympathy  and 
incantation,  and  we  can  but  marvel  at  the  extensive 
sway  of  a  superstition  hardly  superior  to  the  Fetichism 
of  a  race  so  alien  to  ourselves  as  are  the  negroes. 
These  are  only  individual  cases  of  the  very  widespread 
lack  of  judgment,  which  prevails  wherever  the  supposed 
enigma  of  human  existence  is  concerned.  Millions  and 
millions  who  would  turn  away  indignantly  if  required  to 
believe  that  anything  not  entirely  natural  occurred  in  the 
most  complicated  machine,  in  the  most  elaborate  product 


RESULTS  OF   LINGUISTIC  RESEARCH.  3 

of  the  chemical  retort,  or  in  the  strangest  results  of  phy- 
sical experiment,  are  yet  disposed  to  seek  a  dualism 
behind  the  processes  of  life.  Wherever,  also,  the  ex- 
planation of  life,  and  the  reduction  of  vital  phenomena 
to  their  true  natural  causes  is  concerned,  they  would 
wish  to  deny  point-blank  the  possibility  of  such  ex- 
planation or  such  knowledge,  and  to  refer  life  to  an 
unapproachable  and  mystic  domain.  Or,  if  the  solu- 
tion of  the  problem  of  life  be  a.dmitted  in  the  abstract, 
at  least  something  peculiar,  and  a  different  standard  from 
that  by  which  other  living  beings  may  be  measured,  is 
required  for  the  beloved  Self. 

If  we  thus  see,  on  the  one  side,  a  great  portion  of  our 
contemporaries  either  standing  before  the  most  impor- 
tant of  all  problems  in  utter  perplexity  and  helpless- 
ness, or  solving  it  by  the  theology  of  revelation,  we 
may,  fortunately,  point,  on  the  other  side,  to  the  goodly 
host  of  those  who,  since  the  development  of  science 
has  admitted  of  it,  have  encountered  the  investigation 
of  man's  place  in  nature  with  sincere  interest,  and  have 
weighed  the  problem  with  intelligence. 

This  craving  for  a  knowledge  based  on  philosophical 
and  natural  science,  became  apparent  about  a  century 
ago,  and  coincided  with  the  first  beginnings  of  linguistic 
science.  It  is  the  more  appropriate  to  allude  here  to 
this,  as  the  theories  of  the  origin  of  language  are 
profoundly  affected  and  influenced  by  opinions  as  to 
the  origin  of  Man,  and  vice  versa. 

The  result  of  an  inquiry,  made  in  1580,  as  to  the  lan- 
guage of  Paradise,  having  been  that  God  spoke  Danish, 
Adam  Swedish,  and  the  serpent  French,  Leibnitz, 
in  his  letters  to  Newton,  first  attempted  to  regulate  the 


4  THE  DOCTRINE  OF  DESCENT. 

method  of  linguistic  research  by  recommending  as  its 
basis  the  study  of  the  more  recent  and  known  lan- 
guages. And  when,  in  the  middle  of  last  century,  the 
two  opinions,  that  language  was  invented  or  revealed, 
were  sharply  opposed  to  each  other,  and  when  Siissmilch 
(1764),  in  contradiction  to  Maupertuis  and  Jean  J. 
Rousseau,  had  established  that  invention  was  not  possi- 
ble without  thought,  nor  thought  without  language,  and. 
therefore,  that  the  invention  of  language  was  a  self-con- 
tradiction, Herder  opportunely  entered  the  lists  with 
his  work  on  language  (1770),  which  formed  an  epoch  in 
the  science. 

According  to  him,  language  begins  with  imitations 
of  sounds,  at  first  almost  unconscious;  the  tokens, 
as  he  expresses  it,  by  which  the  soul  distinctly  recalls 
an  idea.  He  makes  language  develop  itself  from  the 
crudest  beginnings,  by  the  increasing  need  of  such 
verbal  tokens ;  and  shows  that  with  the  development 
of  mankind,  the  store  of  words  must  also  have  uncon- 
sciously and  instinctively  increased.  The  multiplicity 
of  languages  is  due  to  the  dispersion  of  nations,  whose 
idiosyncrasies  are  reflected  in  the  various  languages. 
Thus  Herder  long  ago  pointed  out  the  importance  ol 
a  psychology  of  nations.  He  was  joined  by  Wilhelm 
von  Humboldt,  whose  opinions  form  the  basis  of  the 
present  science  of  language,  and  who  held  that  the  imi- 
tations of  sounds  are  instinctively  crystallized  into  words, 
and  that  with  this  formation  of  words  and  language 
thought  commences.  It  follows  from  the  nature  of  these 
beginnings,  that  language  is  the  natural  expression  of 
the  spirit  of  a  people ;  that  it  does  not  stand  still,  but 
is  for  ever  in  process  of  transformation. 


WHAT  IS  AFFINITY?  5 

The  science  of  language,  with  its  great  results,  dis- 
plays the  most  important  side  of  human  nature — man 
in  the  elevation  which  he  has  gradually  acquired  above 
the  rest  of  the  living  world — but  it  displays  this  side 
alone.  Although  the  founders  of  hnguistic  inquiry,  of 
whom  we  have  already  spoken,  had  already  represented 
man  as  first  acquiring  reason  and  becoming  man,  by 
means  of  language  proceeding  from  primitive  rudi- 
ments, they  were,  nevertheless,  satisfied  to  assume  the 
privileged  position  of  man  as  an  absolute  endowment, 
or  a  self-evident  axiom.  This  continued  as  long  as 
natural  science  was  limited  to  a  merely  superficial  clas- 
sification of  organisms. 

Man,  as  consisting  of  flesh  and  blood,  seemed,  indeed, 
akin  to  the  higher  animals;  but  so  long  as  their  descent, 
their  actual  consanguinity  was  not  discussed,  so  long  as 
nothing  was  demanded  beyond  their  juxtaposition,  ac- 
cording to  the  analogy  of  their  characteristics,  without 
any  scrutiny  of  the  deeper  causes  of  their  divergence 
or  similarity,  man  indisputably  occupied  the  highest 
grade  in  the  system  of  living  beings.  Linnaeus  places 
man  in  the  order  of  Primates,  together  with  bats,  le- 
murs, and  apes,  without,  on  that  account,  being  accused 
from  pulpit  and  from  chair  of  an  assault  on  the  dignity 
of  mankind.  Bufibn,  Hkewise,  was  able,  unrebuked,  to 
indulge  his  whim,  by  specially  discussing  our  race  in 
his  description  of  the  ass. 

Only  when,  quite  recently,  the  v/orld  became  aware 
that  the  word  "  affinity,"  hitherto  uttered  with  supreme 
indifference,  was  henceforth  to  be  taken  seriously  and 
literally,  since  that  which  is  akin  is  also  the  fruit  of  one 
and  the  same  tree,  a  beam  of  joyful  recognition  thrilled 


6  THE  DOCTRINE  OF  DESCENT. 

through  those  to  whom  man  appeared  a  beuig  com- 
pletely within  the  bounds  of  nature.  But  others,  who 
can  think  of  man  only  as  a  being  absolutely  endowed 
above  his  natural  surroundings,  could  not  fail  to  regard 
as  a  sort  of  crime  the  deduction  which  an  all-embrac- 
ing theory  applied  with  relentless  logic  to  man. 

The  interest  with  which  the  modern  theory  of  kindred 
and  descent  has  been  received  does  not,  therefore, 
proceed  from  friends  alone,  but  quite  as  much  from 
antagonists,  who  perceive,  more  or  less  distinctly,  the 
danger  with  which  the  new  doctrine  threatens  their 
standpoint  of  miracle. 

Even  in  England  the  opposition  to  the  great  Eng- 
lishman, with  whose  name  the  revolution  is  connected, 
has  been  very  considerable,  especially  since  it  became 
evident  that,  true  to  himself,  he  includes  man  also 
within  the  range  of  his  researches,  and  purposes  to 
apply  to  him  all  the  consequences  of  his  doctrine.  But 
it  appears  to  me  that  the  dispute  and  the  agitation  are 
still  keener  on  this  side  of  the  channel,  where  Darwin- 
ism is  meat  and  drink  to  the  daily  papers,  and  to  the 
philosophical  and  theological  periodicals. 

This  phenomenon  is  obvious  to  all  eyes,  and  we 
are  convinced  of  the  deep  importance  of  the  subject 
which,  whether  we  take  part  for,  or  against  it,  must 
influence  our  whole  theory  of  life.  Here  too  that  has 
happened  to  many,  which  so  often  happens  in  ques- 
tions the  difficulties  of  which  are  veiled  by  an  apparent 
general  familiarity.  Every  one  thinks  himself  capable 
of  deciding  about  life,  and,  since  to  non-scientific  per- 
sons the  notorious  relationship  with  apes  is  the  alpha 
and  omega  of  the  doctrine  of  Descent — since  the  most 


REFERENCE  TO   DARWIN.  7 

confused  heads  are  often  most  thoroughly  conv^inced  of 
their  own  pre-eminence — on  no  subject  do  we  so  fre- 
quently hear  superficial  opinions,  mostly  condemnatory, 
and  all  evincing  the  grossest  ignorance. 

I  wish  then  to  render  the  reader  able  to  survey 
the  whole  ramified  and  complicated  problem  of  the 
doctrine  of  Descent,  and  its  foundation  by  Darwin,  and 
to  enable  him  to  understand  its  cardinal  points.  But 
we  must  first  dispose  of  a  preliminary  question  of  uni- 
versal importance  and  special  significance,  which  is 
frequently  ignored  by  philosophical  and  theological 
opponents,  that  is,  the  question  of  the  limits  of  the  in- 
vestigation of  nature.  P'or  if  it  were  an  established  prin- 
ciple that  the  mystery  of  the  living  is  different  from 
that  of  the  non-living,  that  the  former  might  be  disclosed, 
but  that  the  latter  is  shrouded  in  a  veil  which  never  can 
be  raised,  as  is  even  now  so  frequently  asserted,  then, 
indeed,  all  research  directed  towards  the  comprehension 
of  life  would  be  utterly  vain  and  hopeless. 

But  if  the  possibility  of  investigating  life  and  its  origin 
be  not  opposed  by  any  a  priori  scioiples,  still  more,  if 
the  limits  of  investigation  and  knowledge,  which  un- 
doubtedly exist,  are  no  other  for  animate  nature  than 
for  the  inanimate  world  of  matter,  we  may  venture  to 
approach  our  task.  This  will  be  most  adequately  effected 
by  making  ourselves  somewhat  familiar  with  the  object 
of  the  doctrine  of  Descent,  restricting  ourselves,  however, 
to  the  animal  world.  If  I  say  then  that  we  must  obtain  a 
foundation  for  the  theory  of  derivation  or  descent,  for  the 
(loctrire  of  the  gradual  and  direct  development  of  the 
higher  and  now-existing  organisms  from  lower  ancestral 
forms — in  short,  for  the  doctrine  of  the  continuity  of 


8  THE  DOCTRINE   OF   DESCENT. 

life,  we  must  begin  with  a  survey  of  the  animal  forms 
now  spread  over  the  earth.  As  astronomy  begins  with 
the  mere  classification  of  the  stars  and  constellations, 
and  the  knowledge  of  their  apparent  motions,  so  do 
we  also  range  our  material  in  large  groups,  and  this 
in  the  manner  offered  by  the  historical  development  of 
science. 

What  first  strikes  the  observer  of  the  animal  world 
is,  that  it  consists  of  apparently  innumerable  forms. 
The  primary  requirement  is  discrimination  and  arrange- 
ment. In  the  first  stages  of  their  development,  zoology, 
as  well  as  botany  and  mineralogy,  necessarily  consisted 
of  mere  descriptions,  of  a  knowledge  of  objects  in  a 
state  of  completeness.  Physics  and  chemistry,  on  the 
other  hand,  deal  with  the  investigation  of  phenomena 
directly  referring  to  their  origin,  that  is  to  say,  with  series 
of  phenomena  mutually  connected  as  causes  and  effects, 
the  knowledge  of  which,  therefore,  leads  at  once  to 
results  satisfactory  and  tranquillizing  to  the  mind.  This 
description,  at  first  limited  to  the  exterior,  was  gradually 
extended  to  the  interior,  because  zootomy  and  com- 
parative anatomy,  even  m.ore  than  fifty  years  ago,  had 
advanced  so  far  in  the  accumulation  of  endless  details 
that  Cuvier  then  ventured  to  found  the  Natural  System. 

But  this  delineation  of  the  animal  world  required 
completion  on  two  sides,  and,  as  the  science  proceeded 
towards  perfection,  it  received  it  almost  simultaneously 
on  both.  To  the  knowledge  of  the  existence  of  an 
animal  belongs  also  the  description  of  its  origin.  I 
say  emphatically,  "  the  description,"  for  the  history  of 
animal  development  is  not  as  yet  in  itself  a  natural 
science  in  the  same  sense  as  the  mathematico-physicai 


COMPARATIVE   ANATOMY  AND   EVOLUTION. 


sciences  ;  it  is  a  mere  description  of  nature.  But  it 
yields  a  far  more  accurate  knowledge.  In  many  cases 
it  discloses,  for  the  first  time,  the  significance  of  organs, 
and  gives  to  comparative  anatomy  the  confirmation, 
and  frequently  the  possibility  of  interpretation.  The 
v/ing  of  a  bird,  in  its  individual  parts,  may  be  traced 
back  without  difficulty  to 
the  anterior  extremities  of  a 
reptile  or  a  mammal.  But 
the  leg  of  a  bird,  as  a  com- 
plete organ  does  not  har- 
monize with  the  leg  of  other 
vertebrata  until  the  develop- 
m.ent  of  the  bird  in  the  egg 
reveals  that  the  disposition 
of  the  segments  and  of  the 
articulations  is  precisely  the  // i 
same  in  both  cases,  and  that 
the  apparent  anomaly  is 
produced  merely  by  the 
subsequent  anchylosis  of 
bones,  which  generally  re- 
main separate. 

The  complete  leg  of  the 
bird  (A)  shows  us  at  a,  the 
femur,  or  thigh  bone,  and 
at  d,  the  tibia,  or  lower  leg 
bone ;  but  instead  of  the 
bones  of  the  tarsus  and  me- 
tatarsus, the  latter  of  which 
affords   attachment    to   the  fig.  i. 

toes,  we  find  only  the  long  bone  c,   and  at   its  lower 


fO  THE   DOCTRINE  OF  DESCENT. 

extremity  a  small  bone  supporting  the  four  toes.  Earlier 
writers  were  content  to  say  that  the  astragalus  (c)  re- 
places the  tarsus  and  metatarsus.  But  this  is  not  the 
case ;  for  the  chick  in  the  egg  (B)  shows  that  the  bird's 
leg  consists  of  the  thigh,  or  femur  (a),  and  the  shank  or 
tibia  (d),  two  tarsal  (;;2  n),  and  three  or  four  metatarsal 
bones  (c),  and  the  toes,  or  phalanges  ;  that  the  upper 
tarsal  bone  is  anchylosed  with  the  tibia,  and  the  lower 
one  with  the  consolidated  metatarsus.  Only  thus  do 
we  obtain  a  true  perception  of  the  fact  manifested  in 
A,  although  the  cause  of  the  fact  does  not  as  yet 
appear. 

The  next  example  is  rather  more  difficult.  With- 
out the  history  of  development,  comparative  anatomy 
is  incapable  of  explaining  why  man  possesses  three 
little  bones  in  the  auditory  apparatus,  the  bird  only  one. 
The  history  of  development  shows  that  out  of  the  ma- 
terial which  in  man  is  applied  to  the  formation  of  the 
malleus  and  incus,  two  other  portions  of  the  skull  are 
evolved  in  the  bird,  having  little  or  nothing  to  do  with 
the  auditory  mechanism.  In  short,  the  history  of  deve- 
lopment, which  describes  the  gradual  formation  of  the 
organism,  is  at  every  step  a  beacon  to  comparative 
anatomy.  In  itself,  however,  the  history  of  development 
does  not  as  yet  exceed  the  rank  of  a  merely  descriptive 
branch  of  erudition. 

But  if  we  now  perceive  how  the  evolutionary  stages  of 
individuals  represent  series  from  the  lower  to  the  higher, 
analogous  to  the  various  members  existing  side  by 
side  in  the  same  group  of  animals, — how,  for  instance, 
the  mammal  passes  through  stages  at  which  the  lower 
vertebrata   remain  fixed, — a   connection,    at   first  sight 


POSITION   OF   PALAEONTOLOGY.  II 

mysterious,  is  indicated  between  the  evolution  of  the 
individual  and  the  general  constitution  of  the  animal 
world.  This  connection  requires  a  scientific  solution,  a 
reduction  to  causes,  and  -this  all  the  more  urgently  be- 
cause their  relations,  though  as  yet  hidden,  are  rendered 
more  probable  by  a  third  series  of  phenomena,  the 
conquest  of  which  is  likewise  the  achievement  of  natural 
history.  We  allude  to  the  record  of  the  primaeval 
world. 

Therefore,  the  knowledge  of  palceontological  facts 
also  forms  part  of  the  indispensable  basis  of  our  opera- 
tions. Geology  entered  the  right  track  forty  years 
ago.  We  now  know  that  the  world  was  not  made 
backwards,  but  originated  by  gradual  formations  and 
metamorphoses  ;  we  may — nay,  we  must,  infer  that,  at  a 
definite  epoch  of  refrigeration,  life  appeared  in  a  natural 
manner,  that  is  to  say,  without  any  incomprehensible 
act  of  creation  ;  and  during  this  slow  transformation  of 
the  earth's  crust,  we  see  living  beings  also  gradually 
increasing,  difi"erentiating,  and  perfecting  themselves. 

Yet  more.  As  was  first  convincingly  proved  in  detail 
by  Agassiz,  one  of  the  most  vehement  antagonists  of  the 
theory  of  descent,  we  behold  the  palaeontological  or  his- 
torical series  of  organisms  in  the  same  sequence  as  the 
phases  of  the  development  of  the  individual.  There  are 
here  vast  chasms  yet  to  be  filled  up  by  future  observa- 
tion, though  in  many  points  we  must  not  altogether 
despair  of  success.  But  that  the  process  of  palaeon- 
tological development  is,  in  general,  the  one  indicated, 
is  disputed  only  by  naturalists,  who,  like  Barrande, 
years  ago  anchored  themselves  to  inalterable  convictions 
in  science,  as  in  creed,  to  do^^^mas. 


t2  THE   DOCTRINE   OF   DESCENT. 

These  groups  of  facts,  thus  mutually  referring  to  each 
other,  must  be,  in  some  degree,  examined  by  any  one 
desirous  of  understanding  them.  In  other  words,  we 
must  first  review  this  vast  material,  before  we  turn  our 
attention  to  the  magic  spell  which  sifts  and  makes  it 
comprehensible.  The  toil  is  great,  but  the  reward  is 
glorious  !  For,  as  regards  the  organic  world,  the  craving 
inherent  in  the  human  mind  for  the  knowledge  of  reasons 
— the  need  of  causality,  is  satisfied  singly  and  solely  by 
the  doctrine  of  Descent.  As  yet  we  do  not  regard  it  as 
complete ;  in  many  special  cases  it  still  owes  us  an 
answer  ;  but,  on  the  whole,  it  does  as  much  as  any  other 
ingenious  theory  has  done  ;  it  interprets  by  a  single  prin- 
ciple those  great  phenomena  which  without  its  aid  remain 
a  mass  of  unintelligible  miracles.  In  a  word,  it  raises 
the  knowledge  of  organic  nature  to  a  science.  Even  now 
much  of  mere  professional  knowledge  is  wont  to  style 
itself  science.  But  as  the  doctrine  of  Descent  includes 
all  life,  it  cannot  stop  on  approaching  Man.  Were  we 
doubtful  as  to  the  origin  of  language,  or  even  forced  to 
admit  total  ignorance  on  this  point,  we  could  not,  from 
the  existence  of  language,  deduce  the  inapplicability  to 
man  of  the  doctrine  of  Descent,  without,  as  it  seems  to 
us,  arbitrarily  breaking  the  chain  of  ratiocination. 

We  will  now  return  to  the  preliminary  question  already 
indicated,  as  to  the  limits  of  the  investigation  of  nature. 
It  is  the  more  important,  as  incompetent  judges  are 
wont  to  assert,  that  these  limits  are  exceeded.  The 
frivolity  of  the  logic  by  which  such  accusations  are  ren- 
dered plausible  to  the  multitude  surpasses  all  licence. 
We  open,  for  instance,  Luthardt's  "  Apologetic  Lectures 
on  the  Fundamental  Truths  of  Christianity,"  ("Apolo- 


THE   INVESTIGATION   OF   NATURE  AND   MIRACLE.  1 3 

getische  Vortrage  iibcr  die  Grundwahrheiten  des  Christ- 
enthums,")  and  see  how  he  defends  the  reality  of 
miracles.  "  Miracles,"  he  says,  "  are  not  even  miracles. 
They  do  not  even  repeal  the  laws  of  nature  ;  they  merely 
release  single  occurrences  from  the  dominion  of  those 
laws,  and  place  them  under  the  law  of  a  higher  will  and 
a  higher  power.  Of  this  we  have  many  analogies  in  lower 
spheres.  If  my  arm  hurls  a  stone  into  the  air,  this  is 
contrary  to  the  nature  of  the  stone,  and  is  not  an  effect 
of  the  law  of  gravitation,  but  the  interposition  of  a 
higher  power  and  a  higher  will,  producing  effects 
which  are  not  the  effects  of  the  inferior  powers.  These 
powers  and  these  laws  are  not  hereby  repealed,  but  still 
subsist." 

Let  us  pause  a  moment.  To  say  that  it  is  contrary  to 
the  nature  of  the  stone  that  gravity  should  be  apparently 
overpowered  for  a  few  moments  by  muscular  agency,  is 
physically  absurd.  The  stone  remains  the  same  weight, 
its  nature  is  wholly  the  same,  even  while  in  the  motion 
of  projection  ;  and  it  is  utterly  unjustifiable  and  so- 
phistical to  prate  about  muscular  force  as  a  higher 
power  opposed  to  gravity.-  If  the  stone  weighs  two 
hundred-weight,  where  is  the  higher  power  then? 

Rut  when  the  champion  of  supernaturalism  has  mis- 
led and  prepared  his  hearers  by  his  worthless  analogy^ 
he  proceeds  :  "Thus  in  the  miracle,  a  higher  causality 
interposes,  and  evokes  an  effect  which  is  not  the  effect 
of  the  concatenation  of  those  lower  causalities,  and  yet 
.subsequently  submits  to  these  concatenations.  But  this 
higher  causality  ultimately  coincides  with  the  highest 
moral  objects  of  existence.  To  serve  them  is  nature's 
highest  and  most  glorious  pursuit.     Therefore  if  miracle 


14  THE  DOCTRINE  OF   DESCENT. 

Stands  in  connection  with  these  objects,  if  its  conditions 
are  moral  and  not  arbitrary,  it  is  not  contrary  to  nature 
and  its  purpose,  but  in  the  highest  sense  conformable 
to  it." 

Thus  as  soon  as  belief  in  miracle  comes  into  conflict 
with  the  investigation  of  nature,  it  says :  "  You  overstep 
your  limits,  and  must  here  suspend  your  judgment. 
It  is  a  question  of  a  higher  moral  object ;  the  domain 
of  ethics  is  higher  than  that  of  physics,  and  therefore 
a  higher  causality,  which  physicists  have  no  right  to 
criticise,  has  suspended  the  chain  of  cause  and  effect 
with  which  you  naturalists  are  familiar."  This  passage', 
in  which  one  of  the  most  learned  and  honoured 
champions  of  the  beUef  In  miracle  lays  down,  like  a 
sophist,  the  limits  of  the  investigation  of  nature,  is, 
however,  among  the  most  moderate  of  its  kind.  But  our 
point  of  view  and  our  logic  differ  radically  from  that 
of  antagonists  of  this  description,  in  one  particular, 
namely,  that  to  us  the  opposite  to  knowledge  is  igno- 
rance, whereas  they  supplement  knowledge  by  a  so- 
called  higher  knowledge,  and  by  faith. 

While  holding  by  the  maxim  of  Pico  della  MIrandola, 
"  Philosophy  seeks.  Theology  finds,  Religion  possesses 
the  Truth,"  *  it  is  forgotten  that  there  are  truths  and 
truths.  The  subjective  visions  and  sensations  of  sound 
by  which  the  mentally  diseased  are  excited  and  alarmed, 
are  to  them  a  reality,  yet  a  reality  quite  different  to  that 
of  the  sights  and  sounds  received  through  the  healthy 
organs  of  the  senses.  Philosophy  and  science  seek  that 
truth  which  is  deduced  from  the  palpable  connection 
of  things.  But  the  other  truths,  so  often  negatived  by 
the  former,  are  generally  impalpable,   and  are  incom- 


LIMITS  OF  INVESTIGATION.  1 5 

mensurable  with  scientific  truths.      We  will   therefore 
abide  by  the  words  of  Goethe : 

Whoso  has  art  and  science  found. 

Religion,  too,  has  he; 
Who  has  nor  art  nor  science  found. 

His  should  religion  be.* 

And  now,  having  provisionally  averted  uncalled-for 
objections  and  conflicts  with  ambiguous  ideas,  we  may 
quietly  consider  the  limits  of  natural  science.  Let  us 
first  pause  at  the  address  delivered  with  general  approval 
by  the  physiologist  Dubois-Reymond,  at  the  fiftieth 
assembly  of  German  Naturalists  and  Physicians.  He 
made  reference  to  a  passage  in  the  classical  works  of 
Laplace,  in  the  Introduction  to  the  Theory  of  Science, 
which  we  cannot  refrain  from  quoting  in  full.  The 
author  of  the  "Mechanism  of  the  Heavens,"  says:  "Pre- 
sent events  are  connected  with  the  events  of  the  past  by 
a  link  resting  on  the  obvious  principle  that  a  thing  cannot 
begin  to  exist  without  a  cause  which  produces  it.  This 
maxim,  known  by  the  name  of  the  Principle  of  Sufficient 
Cause,  extends  likewise  to  events  with  which  it  is  not 
supposed  to  come  in  contact.  Even  the  freest  will  can- 
not evoke  them  without  a  determining  impulse."  "  We 
must,  therefore,  regard  the  present  condition  of  the  uni- 
verse as  the  consequence  of  its  former,  and  the  cause 
of  its  future,  condition.  A  mind,  for  a  given  moment 
acquainted  with  all  the  forces  which  animate  Nature, 
and  the  reciprocal  relations  of  the  entities  of  which  it  is 

♦  Wer  WissenschaflEl  und  Kunst  besitat. 
Hat  auch  Religion  ; 
Wer  jene  tjeiden  nicht  besilzt, 
Der  habe  Religion. 


f6  THE  DOCTRINE  OF  DESCENT. 

composed — possessed,  moreover,  of  powers  of  compre- 
hension sufficient  to  submit  all  these  facts  to  analysis, 
would  be  able  to  reduce  to  a  single  formula  the  motions 
of  the  largest  heavenly  body  and  of  the  lightest  atom. 
To  such  a  mind  nothing  would  be  uncertain,  and  the 
future,  like  the  past,  would  lie  open  before  it.  The 
human  mind  in  all  the  perfection  which  it  has  been  able 
to  give  to  astronomy,  offers  but  a  faint  image  of  such 
a  mind  as  this."  "All  efforts  of  the  human  intellect  in 
the  search  for  truth  tend  to  approach  the  mind  above 
portrayed,  but  will  always  remain  infinitely  removed 
from  it." 

The  Prussian  physiologist  then  quotes  the  "  Thou 
art  like  the  Spirit  whom  thou  comprehendest"  of  Faust  ;* 
and  is  of  opinion  that,  in  the  abstract,  the  formula  of 
the  universe  is  therefore  not  impenetrable  to  the  human 
intellect.  But  we  own  we  are  cordially  indifferent  to  an 
abstract  perfection  which  never  comes  to  light,  and 
regard  the  unattainableness  of  this  vague  formula  of 
the  universe  as  a  very  endurable  limit  to  human  inquiry. 
But  independently  of  the  dubious  consolation  of  the 
formula  of  the  universe,  we  must  agree  with  Dubois- 
Reymond,  when  he  considers  that  the  limits,  before 
which  the  highest  conceivable  intelligence  must  pause, 
are  also  insurmountable  to  man. 

In  accordance  with  the  views  now  prevailing  among 
physicists  and  biologists,  Dubois-Reymond  has  thus 
specified  the  only  limit  given  to  the  investigation  of 
nature^:  **The  knowledge  of  natural  science,  more  closely 
defined  above,  is  no  real  knowledge.  In  the  attempt  to 
comprehend  the  constant,  to  which  the  mutations  in 

*  Du  gleichst  dem  Geist,  den  du  begreifst. 


ATOMS  IDEALLY  REPRESENTED.  17 

the  material  world  may  be  traced  back,  we  stumble  on 
insoluble  contradictions.  An  atom  contemplated  as  a 
minute,  indivisible,  inert  mass,  from  which  forces  ema- 
nate, is  a  chimera.  In  the  impossibility  of  compre- 
hending the  nature  of  matter  and  force  lies  the  only 
limit  to  the  knowledge  of  natural  science." 

These  propositions  require  some  elucidation.  Eeyond 
the  subdivision  mechanically  possible,  we  must  think  of 
substance  or  matter  as  consisting  of  particles  ultimately 
indivisible.  Of  these  atoms,  according  to  the  present 
standpoint  of  science,  we  are  obliged  to  admit  as  many 
different  species  as  are  not  chemically  reducible  to  more 
simple  elements.  Now  there  is  no  doubt  that  these 
atoms  are,  in  the  actual  sense  of  the  word,  imaginary, 
hypothetical  quantities ;  and  theory  seems  to  indica.te 
that  all  matter,  in  the  most  different  phenomena  in  the 
material  world,  is  based  on  a  single  species  of  atom. 

Every  manual  of  physics  or  physiology  will  show 
that,  in  order  to  understand  and  calculate  the  properties 
of  these  atoms  and  their  combinations  into  the  ingre- 
dients of  compound  bodies,  susceptible  of  chemical 
analysis,  they  are  ideally  represented  under  various 
material  forms,  spherical,  cubical,  &c. ;  furthermore,  that 
in  their  combinations  and  co-operations  as  bodies,  they 
must  be  contemplated  as  surrounded  by  a  rarefied 
atmosphere  of  an  universally  diffused  ether.  But  the 
atom  itself,  and  therefore  the  nature  of  matter,  is 
something  incomprehensible,  unattainable.  In  these 
atoms,  forces  are  inherent,  which  display  themselves  in 
attractions  and  repulsions,  and  in  motion  in  general. 
But  the  final  cause  of  these  motions,  and  how  far  these 
motions  are,  as  it  were,  identical  with  the  existence  of 


£8  THE   DOCTRINE   OF   DESCENT. 

the  atoms,  is  likewise  included  in  the  incomprehensi- 
bility of  matter. 

"  If  we  pass  over  this,"  says  Dubois-Reymond  again, 
"  the  universe  is  approximately  comprehensible.  Even 
the  appearance  on  the  earth  of  life  in  the  abstract  does 
not  render  it  incomprehensible.  For  life  in  the  abstract, 
contemplated  from  the  standpoint  of  the  theoretical 
investigation  of  nature,  is  merely  the  arrangement  of 
molecules  in  a  state  of  more  or  less  stable  equilibrium, 
and  the  introduction  of  an  exchange  of  material,  partly 
by  their  own  elastic  force,  partly  by  motion  trans- 
ferred from  without.  It  is  a  misapprehension  to  see 
anything  supernatural  in  this.'* 

This  is  the  point  which  is  usually  contested  with  the 
greatest  vehemence.  If  all  the  motions  and  states  of 
quiescence  of  the  inanimate  world  can  be  thoroughly 
explained,  the  inexplicable  must  commence  with  the 
basis  of  life.  The  imputation  cast  upon  the  reasoning 
powers  by  this  assumption  may  be  formularized  as 
follows,  in  the  question  put  by  another  sound  and 
thoughtful  physiologist,  A.  Fick  :  *  "  Are  the  charac- 
teristics of  such  a  particle,  as  already  explained, 
applicable  and  effective  during  the  period  of  its  sojourn 
in  an  organism  ?  Thus,  for  instance,  will  the  motions 
of  a  particle  of  oxygen  be  affected  and  altered  by  a 
neighbouring  particle  of  hydrogen,  in  accordance  with 
the  same  laws,  when  one  or  both  form  part  of  an 
organism,  as  when  they  are  out  of  it .? " 

To  reply  in  the  negative  is  to  avow  the  vitalistic 
conception  of  life,  that  is,  to  take  refuge  in  unknown 
forces  quite  extraneous  to  matter,  and  to  admit  that 
the   self-same   particle   can  vary  its   nature,  according 


HEAT,   A   xMODE  OF   MOTION.  I9 

to  vihctliei  it  be  internal  or  external  to  an  organism, 
is,  in  other  words,  to  affirm  a  miracle.  If  this  is  weighed 
against  the  physical  view,  *'  which  in  its  perfection 
reduces  every  organic  process  to  a  problem  of  pure 
mechanics,"  it  may  be  done  in  the  certainly  impartial 
words  of  the  naturalist  just  quoted  :  "  I  am  of  opinion 
that  the  mechanical  view  of  organic  life  is  demonstrated 
only  when  all  the  motions  in  an  organism  are  shown  to 
be  the  effects  of  forces,  which  at  other  times  also  are 
inherent  in  the  atoms.  But  similarly  I  should  regard 
the  vitalistic  view  as  proved,  if  in  any  case  a  particular 
motion  actually  observed  to  take  place  in  an  organism 
were  shown  to  be  mechanically  impossible.  At  pre- 
sent, neither  is  to  be  thought  of.  Nevertheless,  if  a 
decision  must  be  made  without  full  proof,  I  provisionally 
profess  myself  unequivocally  in  favour  of  the  mechanical 
view.  Not  only  does  it  recommend  itself  a  priori  by 
its  superior  probability  and  simplicity,  but  the  progress 
of  scientific  development  raises  it  almost  to  a  certainty. 
When  it  is  seen  how  certain  phenomena — such  as  the 
evolution  of  animal  heat,  which  it  was  formerly  believed 
could  be  explained  only  by  vital  force — are  now  ascribed, 
even  by  those  who  in  general  assume  the  existence  of 
a  special  vital  force,  to  the  universally  active  forces  of 
the  material  particles,  we  find  ourselves  almost  forced 
to  the  conviction  that  by  degrees  all  the  phenomena 
of  life  will  become  susceptible  of  mechanical  explana- 
tion." 

For  the  elucidation  of  the  example  just  given  of  animal 
heat,  let  us  observe  that  modern  physics  have  learnt  to 
know  heat  as  a  peculiar  mode  of  motion.  The  motion 
of  the  hammer  as  it  falls  upon  the  anvil  is  not  lost,  but 


20  THE  DOCTRINE  OF   DESCENT. 

is  transformed  into  the  atomic  motion  of  the  places 
struck,  a  motion,  invisible,  it  is  true,  but  sensible  as 
heat.  But  likewise  the  combination  of  the  particle  of 
oxygen  introduced  into  the  animal  body  by  the  respi- 
ration, with  the  un-oxygenated  constituents  of  the  blood, 
is  a  motion  subject  to  computation,  and  manifesting 
itself  as  oxydation,  combustion,  or  the  evolution  of 
animal  heat.  This  chemical  act  of  combustion  keeps 
the  animal  steam-engine  in  motion. 

In  this  way,  by  the  application  of  mechanical  prin- 
ciples, modern  physiology  has  traced  to  their  causes  a 
great  number  of  organic  processes,  and  the  phantom  of 
vital  force,  which  formerly  reigned  paramount  over  the 
whole  intestinal  canal,  incited  the  glandular  cells  and  the 
muscular  fibres  to  their  offices,  and  glided  along  the 
nerves,  now  scarcely  knows  where  to  breed  disturbance. 

Thus  the  investigation  of  nature  does  not  shrink  from 
enrolling  life  and  the  processes  of  life  in  the  world  of  the 
comprehensible.  We  are  foiled  only  at  the  conception  of 
matter  and  force.  But  we  are  much  further  advanced 
than  Schopenhauer  and  his  adherents,  who  for  the  idea  of 
Force  substitute  that  of  Will ;  for  we  have  analyzed  into 
their  several  self-conditioned  momenta  a  multitude  of 
processes,  which  the  word  "  Will,"  incomprehensible  in 
itself,  is  supposed  to  explain  in  their  totality  ;  and  much 
further  also  than  the  fashionable  philosopher  of  the  day, 
von  Hartman,  who  regales  us  with  the  agency  of  the 
**  unknown  "  in  the  domain  of  the  organic  world. 

"And  yet,"  Dubois-Reymond  thus  formulates  another 
limit,  "  a  new  incomprehensible  appears  in  the  shape  of 
consciousness  even  in  its  lowest  form,  the  sensation  of 
desire  and  aversion.     It  is,  once  for  all,  incomprehen* 


CONSCIOUSNESS.  ?1 

sible  how,  to  a  mass  of  molecules  of  nitrogen,  oxygen, 
hydrogen,  carbon,  phosphorus,  and  so  on,  it  can  be 
otherwise  than  indifferent  how  they  lie  or  move  ;  here, 
therefore,  is  the  other  limit  to  the  knowledge  of  natural 
science.  Even  the  mind  imagined  by  Laplace  cannot  go 
beyond  this,  to  say  nothing  of  our  own.  Whether  the 
two  limits  to  natural  science  are  not,  perchance,  identical, 
it  is,  moreover,  impossible  to  determine." 

In  these  last  words  the  possibility  is  indicated  that 
consciousness  may  be  an  attribute  of  matter,  or  may 
appertain  to  the  nature  of  the  atoms.  And  we  may 
add,  that  the  attempt  has  of  late  been  repeatedly  made 
to  generalize  the  sensory  process,  and  to  demonstrate 
it  to  be  the  universal  characteristic  of  matter,  as  by 
von  Zollner,  in  his  work  on  the  Nature  of  Comets, 
which  has  created  such  a  justifiable  sensation.  He 
holds  that,  if  by  means  of  delicately-formed  organs 
of  sensation  it  were  possible  to  observe  the  molecular 
motions  in  a  crystal  mechanically  injured  in  any  part, 
it  could  not  be  unconditionally  denied  that  the  motions, 
hereby  excited,  take  place  absolutely  without  any  simul- 
taneous excitement  of  sensation.  We  must  either  re- 
nounce the  possibility  of  comprehending  the  pheno- 
menon of  sensation  in  the  organism,  or  "  hypothetically 
add  to  the  universal  attributes  of  nature,  one  which 
would  cause  the  simplest  and  most  elementary  opera- 
tions of  nature  to  be  combined,  in  the  same  ratio,  with 
a  process  of  sensation." 

It  might  be  imagined  that  reflections  of  this  kind 
would  lead  to  the  delusive  abysses  of  speculation ;  but 
if,  still  speaking  only  of  organisms,  we  descend  from 
the  manifestations  elicited  by  sensations  of  desire  and 


22  THE  DOCTRINE  OF  DESCENT. 

aversion  in  the  higher  consciousness  of  man  and  of  the 
superior  animals,  till  we  see  all  reaction  to  external  ex- 
citation dwindle  into  the  scarce  perceptible  motions  of 
the  simplest  protoplasmic  animalculse,  it  is  evident  that 
there  can  be  no  question  here  of  either  consciousness 
or  will.  We  cannot  then  separate  the  idea  of  those 
sensations  of  desire  and  aversion,  by  which  mo- 
tions are  excited,  from  the  elementary  attributes  of 
matter,  as  we  are  wont  to  do  with  regard  to  the 
higher  animals.® 

In  precisely  the  same  sense,  it  was  said  some  years 
ago  by  one  of  the  most  talented  investigators  of  lan- 
guage— Lazarus  Geiger,  now  unfortunately  deceased  :  ^ 
"  But  how  is  it,  if  further  down,  below  the  world  of 
nerves,  a  sensation  should  exist  which  we  are  not  capa- 
ble of  understanding?  And  it  probably  must  be  so. 
For  as  a  body  that  we  feel  could  not  exist  unless  it 
consisted  of  atoms  that  we  do  not  feel,  and  as  we  could 
not  see  a  motion  were  it  not  accompanied  by  waves 
of  light  which  we  do  not  see,  neither  could  a  complex 
living  being  experience  a  sensation  strong  enough  for 
us  to  feel  it  also,  in  consequence  of  the  motion  by 
which  it  is  manifested,  if  something  similar,  though  far 
weaker  and  imperceptible  to  us,  did  not  occur  in  the 
elements,  that  is  to  say,  in  the  atoms.  If  we  only  con- 
sider that  we  are  as  little  capable  of  knowing  that  the 
falling  stone  feels  nothing,  as  that  it  does  feel ;  it  is 
fully  open  to  us  to  decide,  in  accordance  with  the 
greatest  probability,  that  the  world  is  susceptible  of 
explanation." 

We  have  examined  the  limits  which  the  investigation 
of  nature  has  prescribed  for  itself.     The  organic  world, 


MAN   HAS   RISEN   FROM  A  LOWER  GRADE.         23 

far  from  rearing  itself  before  us  as  an  incomprehensible 
entity,  invites  us  to  fathom  its  nature,  and  promises  to 
reflect  fresh  light  upon  the  inanimate  world. 

We  must  now  pass  in  review  a  great  portion  of  ani- 
mate nature,  and  shall  then  arrive  at  the  same  con- 
clusion as  the  linguistic  inquirer,  to  whom — we  again 
quote  his  words — "  it  became,  on  historic  grounds,  incon- 
trovertibly  certain  that  man  has  risen  from  a  lower,  3 a 
animal  grade." 


24  THE  DOCTRINE  OF  DESCENT. 


II. 

The  Animal  World  in  its  Present  State. 

In  order  to  approach  the  doctrine  of  Descent,  and  to 
prepare  for  its  necessity,  we  purpose  next  to  pass  in 
review  a  main  part  of  its  object, — the  present  condition 
of  the  animal  world  in  its  general  outlines.  Organisms, 
as  every  one  may  see,  are  distinguished  from  animate 
bodies  by  a  certain  mutability  of  existence  ;  a  sequence 
and  alternation  of  phenomena,  combined  with  constant 
absorption  and  expulsion  of  matter.  These  changes, 
which  are  ultimately  molecular  motions,  and  are  there- 
fore calculable,  definable,  and  susceptible  of  investiga- 
tion, take  place  in  particles  in  a  state  of  saturation — that 
is  to  say,  soaked  in  water  and  aqueous  fluids  ;  and  this 
peculiar,  yet  purely  mechanical  condition,  suffices  for  the 
explanation  and  comprehension  of  many  of  the  neces- 
sary phenomena  of  life.  Experience  shows  that  this 
capacity  for  saturation,  and  this  mobility,  essentially 
characterize  the  combinations  of  carbon  ;  and  the  sum 
of  these  motions  and  displacements,  of  which  a  great 
part  has  already  been  susceptible  of  mathematically  cer- 
tain investigation,  is  termed  Life. 

Now  it  is  impossible  to  resist  the  impression  that 
there  are  simple  and  composite,  lower  and  higher,  living 
beings  ;  and  we  likewise  feel,  more  strongly  than  words 
will  express,  a  certain  antithesis  between  the  plant  and 


LOWER  FORMS   OF   LIFE.  2$ 

the  animal.     Poetically  regarded,  the  plant  is  the  passive 
organism  as  described  by  Riickert : 

•*  I  am  the  garden  flower 
And  meekly  bide  the  hour, 
The  guise,  with  which  you  come 
Within  my  narrow  room."  * 

The  antithesis  of  the  passive,  quiescent  plant  and  the 
pugnacious  active  animal  diminishes,  however,  as  we 
descend  in  the  scale  of  both  kingdoms.  The  more 
highly  developed  animal  evinces  its  animal  nature  by 
the  vivacity  with  which  it  reacts  to  external  influences 
and  excitations.  In  the  lower  animals  the  phenomena 
of  life  assume  a  more  vegetal  character,  and  in  many- 
groups  of  lower  beings,  which  Haeckel  has  recently 
comprised  under  the  name  Protista,  we  see  the  pro- 
cesses of  metamorphosis  of  tissue,  nutrition,  and  repro- 
duction taking  place,  indeed,  but  in  a  manner  so  simple 
and  undifferentiated,  that  we  too  must  attribute  to  these 
beings  a  neutral  position  betwixt  plants  and  animals. 
We  gain  the  conviction  that  the  roots  of  the  vegetal 
and  animal  kingdoms  are  not  completely  sundered,  but, 
to  continue  the  simile,  merge  imperceptibly  into  each 
other  by  means  of  a  connective  tissue.  In  this  inter- 
mediate kingdom,  I  still  believe  that  the  **  primordial 
slime "  (Urschleim),  or  Bathybius,  has  a  right  to  hold 
a  position.  Many  thousand  cubic  miles  of  the  sea- 
bottom  consist  of  a  slime  or  mud  composed  in  part 
of    manifestly    earthy     inorganic    portions,     in     part     of 

*  "  Ich  bin  die  Blum  im  Garten 
Und  muss  in  Demuth  warten, 
Wann  und  auf  welche  Weise 
Du  trittst  in  meine  Kreise." 


26  THE   DOCTRINE   OF  DESCENT. 

peculiarly  formed  calcareous  corpuscles,  still  perhaps  am- 
biguous in  their  nature  (the  Coccoliths  and  Rhabdoliths), 
and  finally,  which  is  the  main  point,  of  an  albuminous 
substance. 

This  slime,  the  so-called  Bathybius,  does  not,  however, 
exhibit  individuality,  or  the  definiteness  of  a  separate 
existence ;  it  resembles  the  shapeless  mineral  substances, 
each  particle  of  which  bears  the  characteristics  of  the 
whole. 

The  conception  of  an  organism  as  a  being  composed 
of  various  parts,  with  various  offices  or  functions,  and 
appearing  under  a  definite  form  gradually  developed,  is 
in  our  day  so  inherent  and  intuitive,  that  it  is  only  with 
great  exertion  that  we  are  able  to  accommodate  our- 
selves to  the  idea  of  a  living  mass  either  absolutely 
formless  and  undefined,  or  defined  arbitrarily  and  acci- 
dentally. Let  any  one,  who  either  cannot  or  will  not 
do  this,  pause  for  a  moment  to  contemplate  another 
simple  being — for  instance,  Haeckel's  "  Protamoeba." 
A  small  albuminous  mass  increases  by  the  absorption 
of  nutriment,  and  by  the  appropriation  of  matter,  until 
it  reaches  a  certain  circumference,  and  then  propagates 
itself  by  spontaneous  fission  into  two  equal  parts.  To 
our  means  of  observation,  these  and  similar  beings  are 
the  simplest  organisms  devoid  of  organs.  While  ac- 
centuating the  limits  of  research  as  restricted  by  inade- 
quate means  of  observation,  we  maintain  the  validity 
of  RoUet's  retort,^  that  our  reason  cannot  properly 
admit  such  homogeneous  organisms,  performing  all  the 
functions  of  life  solely  by  means  of  their  atomic  con- 
stitution ;  that  we  are  dealing  with  the  still  utterly 
unknown    structure    of  the    molecules   formed   by  the 


PROTISTA,  27 

aggregation  of  atoms  ;  and  that  if  Briicke  says,  "  Apart 
from  the  molecular  structure,  we  must  also  ascribe  to 
h'ving  cells  another  structure  of  a  different  order  of  com- 
plexity, and  this  is  what  we  denote  by  organization," 
we  must  likewise  ascribe  this  yet  unknown  combination 
to  the  Monera  of  Haeckel. 

But  independently  of  this  complexity  of  the  molecular 
structure,  it  is  of  extreme  importance  to  the  investiga- 
tion of  animate  nature  to  have  become  acquainted  with 
bodies  which  present  the  simplest  structure  to  the  as- 
sisted eye,  and  to  anatomical  research.  The  substance 
which  characterizes  them  is  found  again  in  plants  as 
well  as  in  animals  ;  and  plants  and  animals  must  now 
be  regarded  as  two  classes  of  organisms,  in  which  the 
processes  of  self-preservation  and  reproduction  have,  in 
different  ways,  assumed  the  character  of  a  higher  com- 
plexity and  development,  by  the  differentiation  of  the 
originally  homogeneous  substance  into  various  morpho- 
logical structures  and  organs. 

As  we  shall  have  another  opportunity  of  expressing 
an  opinion  in  regard  to  the  beginnings  of  animal  life, 
and  its  points  of  contact  with  protista  and  plants,  we 
shall  transfer  ourselves  from  the  dubious  boundary  line 
into  the  midst  of  the  animal  kingdom,  in  order  to  master 
our  subject  by  sifting  and  arranging  it. 

The  first  impression  of  infinite  variety  is  succeeded  by 
another,  that  there  are  lower  and  higher  animals.  On 
this  point  complete  harmony  prevails.  For  if,  from  teleo- 
logical  considerations,  invalid  in  our  eyes,  the  nature  of 
every  creature  were  said  to  be  perfect,  that  is,  in  corre- 
spondence with  its  purpose  or  idea,  every  one  takes  it  for 
granted  and  self-evident  that  a  standard  of  excellence 


28  THE   DOCTRINE   OF   DESCENT. 

exists,  without  taking  account  of  the  scale  by  which  it  rises 
or  sinks.  This  standard  will,  however,  soon  be  made  mani- 
fest by  the  comparison  of  a  lower  with  a  higher  animal. 
Let  us  select  the  fresh-water  polype  and  the  bee. 

The  little  animal,  several  lines  in  length,  which  in  our 
waters  usually  lives  adhering  to  a  plant,  is  a  hollow 
cylinder,  of  which  the  body-wall  is  formed  of  two  layers 
of  cells.  The  external  layer  gives  rise  to  fibres  which 
act  as  muscles,  and  to  a  supporting  membrane  which 
may  be  compared  to  a  skeleton.  The  mouth  is  sur- 
rounded by  arms  of  similar  construction,  and  varying  in 
number  from  four  to  six.  The  surface  of  the  body  is 
studded  with  numerous  little  stinging  vesicles,  which 
by  their  contact  stun  any  smaller  animalculae  straying 
within  the  reach  of  the  polype,  and  render  them  an 
easy  prey.  This  is,  in  a  few  words,  the  construction  of 
the  animal.  It  possesses  no  arterial  system,  no  special 
respiratory  apparatus  ;  the  functions  of  the  nerves  and 
the  sensory  organs  are  performed  by  the  individual  parts 
of  the  surface.  Reproduction  is  usually  effected  by  the 
budding  of  gemmules,  which  fall  off  at  maturity,  but 
occasionally  also  by  the  produce  of  very  simple  sexual 
organs. 

On  the  other  hand,  hours  do  not  suffice  to  describe 
the  structure  of  a  bee.  Even  externally,  its  body, 
which  possesses  so  highly  complicated  a  structure,  pro- 
mises a  rich  development  of  the  interior.  The  man- 
ducatory apparatus  can  be  rendered  comprehensible 
only  by  comparison  with  the  oral  organs  of  the  whole 
insect  world.  The  various  divisions  of  the  alimentary 
canal  are  each  provided  with  special  glands.  The  rich 
psychical  life,  all  the  actions  which  imply  intelligence^ 


SYSTEMATIC  ARRANGEMENT.  29 

calculation,  and  perception  of  external  situation,  are 
rendered  possible  by  a  highly  developed  nervous  system, 
and  the  marvellously  complex  sensory  organs  combined 
with  it,  of  which  the  eyes  are  especially  remarkable. 
Independently  of  the  generative  organs,  consisting  of 
manifold  parts  of  greater  or  less  importance,  the  history 
of  the  multiplication  and  development  of  the  bee  de- 
mands a  study  of  itself. 

The  function,  and  therewith  the  rank  and  value,  of  the 
bee's  body  seem  to  us  higher  than  that  of  the  polype  in 
proportion  as  it  is  more  complex.  The  superior  com- 
plexity and  variety  of  the  parts  is  anatomically  evident, 
and  similarly  the  higher  phase  of  the  life.  The  superior 
energy  of  the  existence,  the  functional  capacity  and  per- 
fection of  the  bee  as  contrasted  with  the  feebleness  of 
the  polype,  is  obviously  a  result,  or  more  correctly  an 
expression,  of  the  greater  mechanical  and  physiological 
division  of  labour.  In  one  animal,  as  in  the  other,  life 
is  spent  in  the  function  of  self-preservation  and  the 
maintenance  of  the  species,  or  reproduction  ;  in  both, 
the  cycle  of  phenomena  is  limited,  unbroken  ;  but  the 
means  of  execution  are  very  different,  and  therefore 
the  general  effect  is  different.  In  the  variety  and 
correlation  of  the  organs  destined  for  the  different 
manifestations  of  life,  we  have  a  standard  for  the  rank 
of  the  animals.  This  rank  has  a  twofold  character, 
general  and  special.  In  other  words,  the  position  of 
an  animal  in  the  system  is  defined,  first,  by  the 
general  attributes,  which  it  has  in  common  with  the 
forms  harmonizing  with  it  in  the  main  characters 
of  their  organization ;  and,  secondly,  by  the  more 
special  characteristics,  which  place   the  animal   in   its 


ao  THE  DOCTRINE  OF  DESCENT. 

own  rank  and  station  among  its  own  immediate 
kindred. 

Some  insight  into  this  classification  of  the  animal 
kingdom  is  naturally  indispensable  to  any  one,  w^ho 
wishes  to  test  and  understand  its  reasons,  and  to  render 
an  account  of  it  is  an  essential  part  of  our  task. 

Since  Cuvier's  reconstruction  of  Zoology  in  the  early 
part  of  this  century,  our  science  has  been  familiarized 
with  the  expression  "type,"  or  "fundamental  form," 
introduced,  long  before,  by  Buffon.  Cuvier,  by  ex- 
tensive dissections  and  comparisons,  first  proved  that 
animals  were  not,  as  people  were  formerly  inclined  to 
suppose,  made  on  a  last  or  shaped  upon  a  block ;  but 
that  they  fall  into  several  great  divisions,  in  each  of 
which  expression  is  given  to  a  peculiar  constitution, 
arrangement,  and  distribution  of  the  organs  ;  in  short, 
to  a  peculiar  style.  The  sum  of  these  characteristic 
peculiarities,  as  well  as  the  whole  of  the  species  united 
in  it,  was  termed  a  "  type."  Various  views,  it  is  true, 
even  now  prevail  as  to  the  extent  of  several  of  these  types 
or  families,  as  we  will  already  term  them  ;  but  if  we  dis- 
regard the  dubious,  and  in  many  ways  suspicious,  exis- 
tences, generally  comprised  under  the  name  of  primordial 
animals,  there  is  a  general  agreement  as  to  the  following 
number,  but  less  as  to  the  sequence  of  the  animal  types, 
than  as  to  those  groups,  each  of  which  has  its  peculiar 
physiognomy  and  special  characteristic  structure. 

The  class  Coelenterata  includes  the  Polypes  and 
Medusae,  and  in  the  closest  connection  with  it  stands 
the  interesting  class  of  the  Spongiadae,  especially  in- 
structive as  affording  direct  evidence  of  the  doctrine  of 
Descent.   The  organs  of  these  animals  are  nearly  always 


TYPES   AND   FAMILIES. 


31 


arranged  radially  round  an  axis,  passing  through  the 
dorsal  and  ventral  pole.  The  cavity,  which  in  most 
other  animals — for  instance,  in  man — is  termed  the 
abdominal  cavity,  the  space  between  the  intestinal  wall 
and  the  abdominal  parietes,  is  deficient  in  them  ;  but, 
on  the  other  hand,  from  the  stomach  proceed  in  general 
various  kinds  of  tubes  and  branchia,  which  to  a  certain 
extent  replace  the  abdominal  cavity.     Fig.  2  represents  a 


Medusa,  Tiaropsis  DIadema,  after  Agassiz.    The  darkly- 
shaded  organs  form  the  so-called  coelenteric  apparatus. 

Of  the  Echinoderms,  the  reader  is  probably  ac- 
quainted, at  least  with  the  star-fish  (Asterias)  and  the 
sea-urchin  (Echinus),  of  which  the  general  form  is  like- 
wise usually  radiate.  Besides  a  peculiar  chalky  deposit, 
or  greater  or  less  calcification  of  the  skin  covering,  a 
system  of  water-canals  forms  a  characteristic  of  this 
family.  With  these  are  connected  the  rows  of  suckers, 
which,  by  protrusion  and  retraction,  serve  as  organs  of 
locomotion.  On  account  of  the  radiate  structure  pre- 
vailing among  the  Echinoderms,  Medusae,  and  Polypes, 


32  THE   DOCTRINE   OF  DESCENT. 

Cuvier  believed  them  to  be  more  nearly  related,  and  in- 
cluded them  altogether,  under  the  name  of  Radiata.  This 
similarity,  however,  is  only  superficial,  for  whilst,  on  the 
one  hand,  anatomy  discloses  the  great  difference  of  the 
Coelenterata  and  Echinodermata,  the  history  of  evolution 
still  more  decidedly  banishes  the  Echinodermata  from 
this  position,  and  connects  them  more  closely  with  the 
next  division. 

In  this,  that  of  the  Vermes,  the  systematizer  of  the 
old  school  finds  his  real  difficulty ;  in  so  many  ways  do 
they  deviate  from  each  other,  so  great  is  the  distance 
between  the  lower  and  the  higher  forms  ;  and  after 
deducting  the  distinctive  marks  of  orders,  so  little 
remains  as  a  common  character,  so  variegated  is  the 
host  of  smaller  scattered  groups,  and  even  of  single 
species,  which  demand  admittance  to  the  system  of  the 
Vermes.  If  we  attempt  to  describe  their  typical  nature 
in  a  few  words,  it  must  be  something  like  this  :  The 
Vermes  are  more  or  less  elongated,  symmetric  animals, 
which  possess  no  actual  legs,  but  effect  their  locomotion 
by  means  of  a  muscular  system,  closely  combined  with 
the  integuments,  which  frequently  become  an  actual 
muscular  cylinder.  To  this  we  will  add,  that  the  per- 
plexities and  difficulties  in  reference  to  points  of  classi- 
fication are  transformed  into  sources  of  knowledge  for 
the  adherent  of  the  doctrine  of  Descent. 

The  relations  of  the  previous  family  with  the  type  ol 
the  Articulata  is  so  conspicuous,  that  the  "  kinship " 
of  the  two  was  never  questioned,  even  by  the  older 
zoologists.  The  very  name  of  one,  the  highest  division 
of  the  Vermes,  that  is,  of  the  Annelids,  or  segmented 
worms,  indicate  this  connection.     This  distinctive  mark 


GRADATIONS   WITHIN  THE   TYPE.  33 

of  the  Crustacea,  Arachnida,  Myriopoda,  and  Insecta,  is 
that  their  bodies  are  constructed  of  sharply-defined  rings 
or  segments,  the  legs,  antennae  and  mandibles  likewise 
sharing  in  this  segmented  character,  A  faithful  expres- 
sion of  this  segmentation  is  afforded  by  the  nervous  system, 
which  lies,  ladder-like,  on  the  ventral  side,  that  is,  beneath 
the  intestinal  canal,  only  encircling  the  gullet  with  its 
anterior  loop.  The  display  of  segmentation  is  favoured 
by  a  deposit  of  horny  substance,  which  gives  a  skeleton- 
like  stiffness  to  the  integuments. 

The  direct  reverse  is  shown  in  the  integuments  of 
the  Mollusca,  our  mussels,  snails,  and  cuttle-fish.  For 
although  so  many  are  supplied  with  protecting  scales 
and  shells,  these  are  mere  excretions  from  the  actual 
skin,  which  remains  soft,  and  characteristically  moist 
and  slimy,  owing  to  the  secretions  of  numerous  glands 
contained  in  it,  and  has  an  inclination  to  lay  itself  in 
folds,  and  form  a  mantle-like  investment  to  the  body. 
The  body  therefore  remains  more  or  less  clumsy  ;  it  pos- 
sesses none  of  the  grace  of  the  Articulata,  and  especially 
of  the  insect ;  it  is  destitute  of  segmentation,  and  this 
deficiency  is  likewise  evinced  in  the  nervous  system. 
This  consists  only  of  a  ring,  encircling  the  oesophagus, 
and  a  few  smaller  ganglia. 

We  shall  most  readily  come  to  an  understanding  as 
to  the  Vertebrata,  the  family  with  Avhich  man  is  insepa- 
rably united.  The  essential  part  is  the  vertebral  column, 
that  portion  of  the  internal  and  persistently  bony  or 
cartilaginous  skeleton,  in  which  the  main  portion  of  the 
nervous  system  is  contained. 

It  is  thus  established  that  the  systematic  classification 
of  the  animal  kingdom  is  based  on  certain  prominent 


34  THE  DOCTRINE  OF  DESCENT. 

characteristics  of  form  and  internal  structure ;  and  it  is 
very  easy  to  select  from  every  type  forms  in  which  the 
distinctive  marks,  comprised  in  the  systematic  diagnosis, 
may  be  displayed  in  full  perfection.  But  this  is  imme- 
diately succeeded  by  a  farther  observation,  that  of  gra- 
dations within  the  type.  When  we  previously  compared 
the  polype  and  the  bee,  and  were  obliged  to  assign  to 
each  a  very  different  rank,  a  portion  of  this  difference 
of  grade  is  certainly  due  to  the  difference  of  the  family; 
but  the  forms  united  by  family  characteristics  likewise 
diverge  widely  from  each  other,  and  the  systematist 
speaks  of  lower  and  higher  classes  within  every  type,  of 
lower  and  higher  orders  within  every  class. 

Reason  is  compelled  to  this  by  the  same  considerations 
which  forced  themselves  upon  us  in  the  comparison  of  the 
polype  and  the  bee.  Why  does  the  mussel  stand  lower 
than  the  snail.-*  Because  it  does  not  possess  a  head, 
because  its  nervous  system  is  not  so  concentrated  and 
so  voluminous,  because  its  sensory  organs  are  more  de- 
fective. In  one,  as  in  the  other,  the  structural  material 
is  present  in  quantities  sufficient  for  the  completion  of 
the  type  ;  but  in  the  snail  it  is  more  developed,  and  the 
single  circumstance  of  the  integration  of  various  parts  to 
form  the  head  confers  a  higher  dignity  upon  the  snail. 
It  is  needless  to  illustrate  this  gradation  within  the 
families  by  further  examples  ;  the  most  superficial  com- 
parison of  a  fish  with  a  bird  or  a  mammal,  of  one  of 
the  parasitic  Crustacea  with  a  crayfish  or  an  insect, 
shows,  as  the  older  zoology  represented  it,  that  in  the 
actual  forms  the  ground  plan,  or  "ideal  types,"  find 
very  diversified  expression. 

A  further  result   of  this    descriptive    inquiry  is    the 


I 


TREE-LIKE   GROUPING.  35 

tree-like  grouping  of  the  members  of  the  same  family. 
The  reciprocal  relations  of  the  various  families  can- 
not be  represented  in  a  simple  line ;  though  in  former 
days  more  importance  was  attributed  to  the  general 
indications  of  the  relative  value  of  the  types.  On  the 
other  hand,  descriptive  zoology  had  long  been  compelled 
to  devise  tables  of  affinity  for  the  systematic  subdivisions, 
descending  even  to  species  according  to  the  criterion  of 
anatomical  perfection  ;  and  these  found  expression  only 
in  diagrams  of  highly  ramified  trees.  Branches  ap- 
peared which  terminated  after  a  brief  extension  ;  others 
are  greatly  elongated  with  numerous  side  branches ;  in 
every  branch  characteristic  phenomena  and  series  are 
made  manifest. 

Let  us  attempt  it  with  the  Vertebrata,  for  example. 
Even  with  the  fishes  we  fall  into  great  perplexity ; 
which  to  place  at  the  end  as  being  the  highest  But 
take  which  we  will,  the  sharks  or  our  teleostei,  the  am- 
phibians cannot  be  annexed  in  a  direct  line,  nor  does  the 
elongated  branch  line  of  the  latter  merge,  as  might  be 
imagined,  into  the  reptiles.  The  birds,  on  their  side, 
offer  a  sharp  contrast  to  the  mammals,  and  this  separa- 
tion and  divergence  extend  to  all  the  subdivisions.  We 
must  figuratively  represent  family  branches,  clusters  of 
genera,  and  tufts  of  species,  which  latter  ramify  into 
sub-species  and  varieties.  With  this  representation  of 
the  tree-like  distribution  of  the  system,  we  shall  gladly 
I  evert  to  the  comparison  of  the  members  of  different 
types,  with  reference  to  their  functional  value.  The  bee 
in  itself  is  manifestly  a  far  more  complex  organism  than 
the  lowest  fish-like  animal,  the  lancelet ;  and  in  these  two 
we  compare  a  low  form  of  a  high  type,  and  a  high  form 

4 


^6  THE   DOCTRINE  OF   DESCENT. 

of  a  low  type.  By  varying  and  combining  comparisons  of 
this  sort,  and  taking  account  of  the  points  of  connection 
between  the  various  types,  to  which  we  shall  immediately 
refer,  the  figure  of  the  systematic  trees  completes  itself 
into  one  vast  tree,  of  which  the  main  branches  are  re- 
presented by  the  types. 

Had  the  systematizers  of  the  old  school  been  familiar 
with  the  construction  of  plants  and  animals,  they  would 
have  first  established  the  diagnoses  and  distinctive  cha- 
racters, and  then  called  to  life  the  types  and  their  species: 
for  their  chief  torment  has  been,  that  the  diagnoses  are 
liable  to  so  many  exceptions,  and  that  the  characters 
of  the  fundamental  forms  are  without  any  absolute  value. 
Roughly  and  generally  speaking,  polypes  are  radiate  in 
form,  but  not  a  few  are  bilateral,  or  symmetric  on  two 
sides.  Most  snails  possess  well-marked  mantle-folds,  but 
we  can  scarcely  speak  of  the  mantle  of  many  thoroughly 
worm-like  slugs. 

Head  and  skull  seem  an  inalienable  mark  of  the 
vertebrata,  yet  the  lancelet  has  no  such  head,  but  merely 
an  anterior  end.  Nevertheless,  it  may  be  objected,  it 
has  a  vertebral  column  ;  yet  this,  the  special  badge  of 
nobility  of  the  vertebrate  animals,  like  the  auditory  appa- 
ratus, and  the  notochord,  is,  even  if  only  transiently,  a 
possession  of  the  Ascidians,  a  class  of  animals  which 
in  their  mature  condition  do  not  bear  the  remotest  re- 
semblance to  the  Vertebrata.  When  we  become  aware 
of  these  deviations  from  so-called  laws  of  form  and 
structure,  seemingly  well  established,  we  are  prepared 
for  a  manifest  failure  of  the  system,  in  regard  to  con- 
necting forms,  and  forms  of  uncertain  position  in  the 
system. 


i::termediate  foRxMs.  37 

If  the  result  of  the  systematic  sifting  and  arrange- 
ment within  the  individual  types  can  be  comprised  in 
diagrams  of  trees,  forms  intermediate  to  the  members 
of  the  types,  classes,  orders,  &c.,  follow  as  a  matter  of 
course.  For  if  the  figure  be  correct,  every  ramification 
of  the  branches  must  include  species  diverging  very 
slightly  from  the  species  standing  in  the  lowest  portions 
of  the  bough  from  which  it  branches  off.  And  thus  all 
systematizing,  in  fact,  amounted  to  the  insertion  of  the 
right  intermediate  forms  between  each  two  forms  devi- 
ating from  each  other  in  a  higher  degree  ;  nay,  in  some 
cases,  intermediate  forms  were  sought  where  none  exist. 
The  older  zoology  always  regarded  the  duck-mole  (Or- 
nithorhynchus)  as  the  mammal  most  nearly  allied  to  the 
birds,  though  the  cause  of  the  bird-like  appearance  of 
the  lowest  mammal  known,  is  by  no  means  to  be  sought 
in  a  direct  relationship,  but  in  a  remote  cousinhood. 

But  we  must  draw  attention,  not  to  these  connecting 
forms,  which  natural  history  assumes  as  perfectly  self- 
evident,  but  to  those  which  are,  as  it  were,  inconvenient 
to  systematic  description,  and  threaten  to  render  illusory 
the  groundwork  so  laboriously  gained.  There  are  some 
fish  like  animals,  the  Dipnoi,  (Lepidosirens  and  their 
congeners)  with  the  characters  of  Amphibians.  The 
Infusoria  possess  many  characteristics  of  the  so-called 
primordial  animals,  but  in  other  ways  they  differ  from 
them,  and  point  to  the  lowest  Turbellaria.  A  minute 
animal  inhabiting  our  seas  in  countless  multitudes,  i.e. 
the  Sagitta,  is  neither  a  true  annelid  nor  a  legitimate 
mollusc.  The  Peripatus,  a  creature  recently  and  very 
thoroughly  investigated,  combines  in  a  highly  remarks 
able   manner   the   characteristics   of    the   Articulata ;    for 


38.  THE   DOCTRINE   OF  DESCENT. 

instance,  tracheae  with  those  of  the  Annelida — as  the  lateral 
organs. 

The  combination  is  inexplicable '  and  paradoxical  from 
the  point  of  view  of  the  old  system. 

Example  after  example  might  be  thus  accumulated 
to  show  that  the  rigid  partitions  of  the  system  are 
scarcely  raised  before  they  are  again  broken  down  in 
every  direction  ;  and  this  in  direct  ratio  with  the  increase 
of  special  science.  As  before  said,  descriptive  natural 
history  necessarily  gained  this  experience.  It  then 
spoke  of  exceptions  and  deviations,  without  being  able 
to  adduce  any  reason  why  the  classes  and  types  should 
be  able  to  break  through  their  limits,  and  indeed  most 
frequently  without  feeling  any  need  of  accounting  for 
the  failure  of  the  rigid  systenu 


III. 

Tlie  Phenomena  uf  Reproductior.  in  the  Animal  World. 

The  faculty  of  giving  existence  to  new  life  is  part  of 
the  evidence  of  life.  A  crystal  does  not  reproduce 
itself,  it  can  only  be  resolved  into  its  elementary  consti- 
tuents ;  and  in  the  natural  course  of  things,  or  in  an 
artificial  manner,  these  may  be  induced  to  form  another 
crystalline  combination.  But  this  is  not  that  con- 
tinuity of  reproduction  which  links  individual  to  indivi- 
dual, is  not  procreation  wrapped  in  a  cloud  of  mystery. 
Herein,  it  seems,  consists  a  stubborn  opposition.  Yet, 
if  the  distinction  between  animate  and  inanimate  nature 
has  been  recognized  as  one  not  entirely  absolute ; 
especially  if  the  possibility,  nay  even  the  necessity,  has 
been  perceived  of  the  primordial  generation  or  parent- 
less  origin  of  the  lowest  organic  beings  from  inorganic 
matter  (of  which  more  hereafter),  and  if  the  nature  of 
nutrition  and  growth  is  understood  to  be  entirely 
dependent  on  the  power  of  obtaining  material, — the 
mystery  of  reproduction  henceforth  disappears.  Gene- 
ration is  no  longer  a  mystical  event ;  and  the  origin  of 
an  organism  in  or  from  an  organism,  the  emission  or 
development  of  innumerable  germs,  may,  like  the 
origin  of  a  new  crystal,  be  analyzed  into  the  motions 
of  elements,  as  yet  accessible  only  to  the  eye  of  imagi- 


40  THE   DOCTRINE  OF   DESCENT. 

nation.  By  this  we  mean  to  say  that  in  the  province  of 
reproduction  the  Hmits  of  inquiry  are  neither  narrow 
nor  pecuHar.  We  will  therefore  now  proceed  to  describe 
the  process  of  reproduction  and  development  in  the 
animal  kingdom. 

If,  as  must  be  generally  admitted,  the  most  essential 
characteristics  are  common  to  the  highest  and  the  lowest 
life, — and  it  is  only  the  complexity  of  the  vital  processes, 
together  with  the  variety  of  the  parts  by  which  they  are 
performed,  that  give  rise  to  graduated  diversities, — it 
will,  of  course,  be  in  the  simplest  organisms  that  we  shall 
most  readily  recognize  the  nature  of  these  vital  processes. 

The  simplest  beings,  discovered  by  Haeckel,  such  as 
the  Protamceba,  those  minute  albuminous  masses  of  sar- 
code,  increase  to  a  certain  extent.  Why  these  dimensions 
should  vary  only  within  definite  narrow  limits,  and  why, 
on  attaining  a  certain  extent,  the  molecules  should 
gravitate  into  two  halves,  we  do  not  know ;  at  any  rate 
it  is  an  affair  of  relations  of  cohesion,  theoretically 
susceptible  of  computation.  It  is  enough  that  at  a 
certain  size  the  coherence  of  the  parts  is  loosened  in  a 
central  zone,  the  individual  becomes  faithless  to  its 
name,  and  divides  into  two  halves,  of  which  each  from 
the  moment  of  separation  begins  an  individual  life, 
while  from  the  commencement  of  the  fission  prepara- 
tions were  being  made  for  their  self-dependence.  This 
is  the  simplest  case  of  reproduction,  a  multiplication 
by  division.  Frequently,  however,  it  does  not  stop 
at  bisection  ;  the  motion  of  the  minute  constituents, 
which  causes  the  fission,  proceeds  in  such  a  manner  that 
the  halves  are  again  divided,  and  the  quarters  yet  again, 
the  whole  being  thus  divided  into  a  greater  number  of 


FISSION — GEMMiSTION.  4I 

portions,  and  the  parent-creature  is  resolved  into  a 
swarm  of  off-shoots. 

This  multiphcation  by  mere  division  of  the  mass  pre- 
supposes that  the  organism  thus  reproducing  itself  pos- 
sesses no  high  complexity.  The  bisection  of  a  beetle 
or  a  bird  is  inconceivable  as  a  means  of  propagation. 
Yet  Stein's  valuable  observations  on  the  reproductive 
process  of  the  Infusoria,  make  us  acquainted  with 
organisms  standing  far  above  these  simple  so-called 
Monera,  of  which  the  subdivisions  undergo  a  series  of 
profound  metamorphoses,  before  separating  as  self- 
dependent  individuals.  This  transformation,  combined 
with  fission,  leads  to  reproduction  by  gemmation. 

As  the  fission  of  these  low  organisms  depends  on  the 
attainment  of  a  certain  limit  of  growth  conditional  on 
adequate  nourishment,  the  case  now  more  frequently 
occurs  that  the  individual  discharges  the  superfluity  of 
material  obtained  at  a  definite  part  of  the  body,  and 
forms  a  bud  or  gemmule.  We  are  already  acquainted 
with  reproduction  by  gemmation  in  the  simplest  organ- 
ism, the  cell ;  for  all  healing  and  cicatrization  in  higher 
beings,  even  to  the  re-integration  of  the  mutilated  limbs 
of  amphibians,  is  effected  only  by  the  reproduction  by 
fission  and  gemmation  of  the  elementary  morphological 
constituents.  But  it  lies  in  the  nature  of  the  process 
of  gemmation,  that  it  should  extend  far  higher  than 
rission  in  the  scale  of  organisms ;  it  is  the  origination 
of  a  new  being  from  one  already  existing,  the  latter, 
meanwhile,  preserving  its  individuality  wholly  or  for 
the  greater  part,  and  yet  being  able  to  transfer  to  the 
progeny  its  own  characteristics  in  their  full  integrity. 

The  simplest  case  of  gemmation  is  where  the  parent 


42  THE  DOCTRINE  OF  DESCENT. 

animal  produces  one  or  more  gemmules  similar  to  itself, 
capable  in  their  turn  of  producing  similar  gemmules.  Of 
this,  every  collection  of  corals  gives  numerous  examples, 
and  shows  how  the  diversified  appearance  of  the  several 
genera  of  coral  depends  merely  on  minor  modifications 
of  this  mode  of  reproduction.  Yet  single  corals  exist 
in  which,  on  careful  comparison,  not  only  may  accidental 
deviations  be  already  discerned,  but  regularly  recurring 
variations  between  parent  and  progeny,  as  Semper  has 
recently  shown  in  Madrepores  and  Fungiform  corals. 
This  brings  us  to  the  highly-important  phenomenon  of 
Alternate  Generation,  which  we  must  elucidate  by  a 
few  examples  before  entering  upon  the  nature  of  sexual 
reproduction. 

Figure  3  shows  in  A  a  polype-shaped  being  with 
cruciform  tentacles,  on  which  its  discoverer,  Dujardin, 
bestowed  the  generic  name  of  Cross-polype,  or  Stauri- 
dium.  This  animal,  growing  like  a  polype  upon  a  stalk, 
forms  above  its  lower  cross,  gemmules  which  make  their 
appearance  as  spherical  balls,  gradually  assume  a  bell-like 
shape,  and  detach  themselves  on  attaining  the  structure 
and  form  of  a  Medusa  or  sea-nettle.  The  Medusa  (termed 
Cladonema  Radiatum,  Fig.  3  B)  is  thus  the  offspring  of 
its  utterly  dissimilar  parent,  the  Stauridium  ;  it  repro- 
duces itself  in  the  sexual  method,  and  from  its  eggs 
proceed  Stauridia.  The  two  generations  thus  alter- 
nate; the  cross-polype  is  an  intermediate  generation  in 
the  development  of  the  Medusa,  so  that  the  sexual  genera- 
tion never  originates  directly  from  its  egg. 

In  the  tape-worm,  we  have  an  illustration  of  the  same 
process,  only  in  a  somewhat  more  complicated  form. 
It  is  known  that  from  the  intestinal  canal  of  individuals 


ALTERNATE  GENERATION. 


43 


afflicted  with  tape- worm,  issue  so-called  somites  or  seg- 
ments of  the  tape-worm.  These  somites  are  usually 
filled  with  such  an  extraordinary  number  of  ova  that 
they  seem  like  mere  packets  of  eggs.     It  appears,  how- 


FIG.   3. 


ever,  from  the  evolutionary  history  of  the  tape-worm, 
and  its  relations  with  other  annulosa,  namely  with 
leecheij  and  Turbellaria,  that  notwithstanding  their  in- 
completeness and  deficiency  of  organs,  these  somites  are 
equivalent  to  sexually  mature  individuals  ;  or,  according 
to  Haeckel's  definition,  are  endowed  with  personality. 
If  the  tape-worm  now  comported  itself  like  most  other 
animals,  somites  would  be  directly  developed  from  its 
eggs.     But  to  this  there  is  a  very  circuitous  proceeding. 


44  THE  DOCTRINE   OF   DESCENT. 

If  the  egg  of  a  tape-worm,  by  chance  and  good  luck, 
strays  into  a  congenial  stomach, — for  example,  the  egg 
of  the  human  tape-worm,  Toenia  solium,  into  the  stomach 
of  a  pig,  the  embryo  wanders  out  of  the  stomach  in 
which  it  quitted  the  egg,  and  makes  its  way  into  the 
muscles,  where  it  swells  out  into  a  sort  of  cyst.  This 
cyst  is  the  first  intermediate  generation.  It  produces  a 
peg-shaped  gemmule,  which,  however,  fails  of  its  object 
as  long  as  the  "  bladder  worm,"  or  "  Gargol,"  remains  in 
the  flesh  of  the  pig.  It  is  only  when  this  comes,  raw  or 
imperfectly  cooked,  into  the  human  stomach,  that  the 
time  has  arrived  for  the  release  of  the  pupa.  It  emerges 
from  its  parent  the  cyst,  and  the  pupa,  in  which  we  nov/ 
recognize  the  head  and  thorax  of  the  tape-worm  imago, 
represents  a  second  intermediate  generation.  Its  pro- 
ductiveness is  forthwith  displayed;  it  becomes  elon- 
gated, and  as  its  ribbon-like  form  increases,  shooting 
out  from  the  posterior  portion  of  the  cervix,  the  more 
distinctly  marked  become  the  transverse  stripes  and 
"  somites  ;"  in  other  words,  the  individuals  of  the  third 
or  sexual  generation. 

In  the  evolutionary  cycles  just  discussed,  there  is  an 
alternation  of  asexual  and  sexual  reproduction ;  and 
before  examining  some  other  cases  of  asexual  multi- 
plication, we  must  make  ourselves  acquainted  with  the 
facts  of  sexual  reproduction. 

The  characteristic  of  this  is,  that  it  requires  for  the 
generation  of  the  new  individual  the  union  of  two 
different  products  or  morphological  elements,  the  ovum 
and  the  sperm.  The  ovum  is  always,  in  the  first  in- 
stance, a  simple  cell,  of  which  the  nucleus  is  termed  the 
germinal   vesicle,  and    the  nucleole  the  germinal  spot. 


GERM-CELLS.  45 

In  manyanimals  it  is  provided  with  a  sheath  or  membrane 
of  its  own  ;  in  others  it  remains  naked,  and  in  that  case 
frequently  displays  the  remarkable  movements  of  pro- 
toplasm. The  germ-cells  of  different  classes  of  animals 
vary  considerably  in  their  microscopic  dimensions ; 
nevertheless,  in  the  whole  animal  kingdom,  from  the 
sponges  and  polypes  up  to  the  mammals  inclusive  of 
man,  they  are  essentially  similar.  Nor  do  non-essential 
differences  appear  until  the  primitive  germ-cell  is  more 
abundantly  provided  with  yelk  and  albumen,  and  has 
surrounded  itself  with  a  specially  thick  and  perforated 
shell,  as  in  insects  and  fishes,  or  with  a  peculiarly 
formed  sheath,  in  the  shape  of  a  double  concave  lens, 
as,  for  instance,  in  some  Turbellaria.  As  a  rule,  the 
ova  are  formed  in  special  organs, 
the  ovaries.  The  other  sexual 
element,  the  sperm,  contains,  as 
its  peculiar  active  constituents, 
the  spermatozoa  (fig.  4  s),  which 
consist  of  a  pointed,  elliptic,  or 
occasionally  of  a   hook-shaped,  ^'^-  ^■ 

head,  and  a  thread-like  body.  As  long  as  the  sperm 
is  capable  of  fecundation,  the  filamentous  appendage 
performs  serpentine  movements,  and  the  development 
of  the  spermatozoa  from  cells,  as  well  as  the  comparison 
of  their  movements  with  the  vibrating  movements 
of  ciliated  and  flagellate  cells,  enable  us  to  recognize 
them  also  as  modified  cell  structures.    , 

The  vehement  dispute  of  last  century  between  Evo- 
lutionists and  Epigenists  has  now  a  merely  historical 
interest.  The  former  maintained  that  either  in  the  ovum 
or   in  the  sperm-corpuscle   the  whole  future  organism 


46  THE  DOCTRINE  OF  DESCENT. 

was  prefigured  in  all  its  parts,  and  that  it  hence  required 
only  the  development  of  the  infinitely  minute  organs 
already  existing.  The  others,  who  carried  off  the  victory, 
saw  in  the  ovum  the  yet  undifferentiated  material  which 
subsequent  to  fecundation  had  still  to  be  transformed  into 
the  various  morphological  elements  and  organs.  But  it 
is  scarcely  twenty  years  ago  since  the  process  of  fecunda- 
tion was  discovered,  and  since  it  was  proved  that  at  least 
one  sperm  corpuscle,  and,  as  a  rule,  several  or  many, 
must  penetrate  into  the  interior  of  the  ovum  and  unite 
materially  with  its  substance  in  order  to  produce  an 
effectual  fecundation. 

The  course  of  our  demonstration  obliges  us  to  place 
sexual  in  sharp  contrast  with  asexual  genesis.  But 
here,  again,  recent  times  have  produced  a  series  of 
equalizing  and  conciliatory  observations  which  must 
not  be  neglected  by  us,  bent  as  we  are  on  tracing  the 
antecedents  of  the  doctrine  of  evolution,  and  demon- 
strating the  transition  taking  place  throughout  organic 
Nature.  In  the  cases  of  alternate  generation  selected 
above,  the  generations  which  do  not  produce  ova  and 
spermatozoa,  reproduce  themselves  by  external  gemma- 
tion. Now,  there  is  manifestly  no  great  physiological 
difference  if  the  deposition  of  the  material  from  which 
the  progeny  is  formed  takes  place,  not  externally,  but 
in  and  by  special  internal  organs.  One  of  the  most 
familiar  examples  occurs  in  the  evolutionary  cycle  or 
alternate  generation  of  the  genus  Distoma  of  the 
Entozoa.  In  the  ventral  cavity  of  one  larval  genera- 
tion arise  cell-spheres,  or  germs,  which  develope  into 
the  second  generation — the  Cercaria. 

Great  excitement  was    likewise  aroused  by  the  dis- 


DEVELOPMENT  OF  UNFERTILIZED   OVA.  4/ 

covery  of  the  germ-formation  of  the  larvae  of  some  di- 
pterous insects  (Cecidomyia,  Miastor).  In  the  ventral 
cavity  of  the  maggots  of  these  flies  arises  a  second  gen- 
eration of  maggots,  of  which  the  origin  was  primarily 
attributed  to  a  simple  germ-formation,  until  it  was 
shown  that  these  germs  proceed  from  the  situation  of 
the  sexual  glands  (which  in  many  insects  are  deve- 
loped at  a  very  early  stage),  and  must  therefore  be 
regarded  as  unfertilized  ova.  The  second  generation 
of  maggots  lives  at  the  expense  of  its  parent,  consumes 
its  fatty  substance,  and  afterwards  destroys  the  other 
organs  ;  while  of  the  pelican-like  parent  nothing  finally 
remains  but  the  skin,  as  a  protecting  cover  to  the 
offspring,  which  very  soon  emerges. 

Without  mentioning  other  cases  in  which  it  may  be 
questionable  whether  germs  or  unfertilized  ova  attain 
development,  Ave  will  point  out  a  few  of  those  in  which 
development,  without  fecundation,  is  established  with 
complete  certainty.  The  queen  bee,  partly  from  the 
natural  course  of  its  life,  partly  from  various  accidenis 
in  which  fecundation  could  not  take  place,  lays  regularly 
a  number  of  unfertilized  eggs,  from  which  issue  drones, 
or  male  individuals  ;  or  if  exceptionally  eggs  are  laid 
by  workers,  which  are  imperfectly  developed  female 
bees  not  susceptible  of  fecundation,  these  eggs  likewise 
produce  drones  only.  Von  Siebold's  highly  interesting 
experiments  on  the  reproduction  of  a  wasp  (Polistes 
Gallica),  have  shown  that  the  hybernating  fertilized 
females,  who  found  a  new  colony  in  the  spring,  deposit 
eggs  whence  issue  female  individuals,  and  occasionally 
males  This  virgin  generation  then  produces  eggs  from 
which  males  are  developed.     With  various   butterflies, 


4.8  THE   DOCTRINE  OF   DESCENT. 

on  the  contrary,  the  unfertilized  eggs  produce  females  • 
only ;   and   it   is   the   same  with  several   of   the  lower 
crustaceans. 

We  will  now  revert  to  the  consideration  of  the  evolu- 
tionary processes  displayed  in  sexual  reproduction  after 
fecundation  has  taken  place.  Development  invariably 
commences  with  a  process  of  cell-formation,  the  bifurca- 
tion or  formation  of  the  germinal  membrane,  after  the 
completion  of  which,  instead  of  the  one  primitive  cell, 
a  large  number  of  cells  are  usually  in  existence,  as  the 
material  for  the  distribution  and  construction  of  the 
embryo.  Ova  developing  parthenogenetically,  without 
fecundation,  likewise  commence  their  development  by 
this  multiplication  of  cells ;  and  even  the  ova  of  ani- 
mals, in  which  development  never  takes  place  without 
previous  fecundation,  exhibit  an  incomplete  bifurcation, 
if  not  fertilized  at  a  certain  stage  of  maturity.  This 
process,  it  is  true,  has  been  as  yet  demonstrated  only  in 
the  ova  of  the  frog  and  the  domestic  fowl  ;  but  these 
cases  are  sufficient  to  divest  the  bifurcation  of  the 
character  of  an  independent  phenomenon,  exclusively 
restricted  to  sexual  reproduction. 

Even  before  the  appearance  of  C.  E.  von  Baer's  really 
classical  and  fundamental  work  on  the  "  Evolutionary 
History  of  Animals"  (Entwickelungsgeschichte  der 
Thiere),*  the  view,  founded  on  incomplete  observations, 
had  become  established,  that  in  the  various  stages  of 
their  development  the  higher  animals  passed  through 
the  forms  of  the  lower  ones.  In  this,  natural  philosophy 
did  not  confine  itself  to  the  limits  of  the  types  ;  and 
hence  did  not  pause  at  the  hypothesis  that  the  mam- 
malian embryo  was  successively  a  fish,  an  amphibiaa 


TYPES  OF  DEVELOPMENT.  49 

and  in  a  certain  sense,  by  a  particular  gradual  evolution 
of  the  organs,  a  bird  also,  but  made  the  embryo  like- 
wise repeat  and  surpass  the  lower  types.  To  this  false 
tendency,  acting  on  vague  analogies,  a  stop  was  put  by 
the  great  naturalist  just  named.  He  showed  that  a 
number  of  coincidences  might,  indeed,  be  demonstrated 
between  the  embryo  of  the  higher  and  the  permanent 
form  of  the  lower  animals,  but  that  this  resemblance 
rested  essentially  on  the  fact  that  in  the  embryo  of  the 
higher  animal  the  differentiation  of  the  general  funda- 
mental mass  had  not  yet  set  in,  and  that  in  the  progress 
of  development  it  passes  through  stages  which  are  per- 
'manent  in  the  series  of  inferior  animals. 

On  the  other  hand,  he  positively  repudiated  the  asser- 
tion that  the  embryos  of  the  higher  types  actually  pass 
through  forms  permanent  in  the  lower  ones.  He  says 
that  the  type  of  each  animal  seems  from  the  first  to 
fix  itself  in  the  embryo,  and  to  regulate  its  whole 
development  As  regards  the  vertebrate  animals  in 
particular,  the  further  we  go  back  in  the  history  of  their 
development,  the  more  do  we  find  the  embryos  alike, 
both  on  the  whole  and  in  the  individual  parts.  "  Only 
gradually  do  the  characters  appear  which  mark  the 
greater,  and  later  those  which  mark  the  smaller  divi- 
sions of  the  Vertebrata.  Thus  from  the  general  type 
the  special  one  is  evolved." 

Von  Baer  thus  held  that  the  analogy  consisted  only  in 
the  embryonic  states  of  the  various  animal  forms;  but  he 
was  obliged  to  go  beyond  the  circle  of  the  types,  and  he 
thought  it  probable  that  among  all  embryos  of  verte- 
brate, as  well  as  invertebrate  animals,  developed  from  a 
true  ovum,  there  is  a  conformity  in  the  condition  of  the 


50  THE   DOCTRINE  OF  DESCENT. 

g;erm  at  a  period  when  the  type  has  not  yet  manifested 
itself.  This  led  him  to  the  question,  "Whether,  at  the 
beginning  of  development,  all  animals  are  not  essen- 
tially alike,  and  whether  a  common  primordial  form 
does  not  exist  for  all  ?  "  "  It  might,"  he  finally  thinks, 
"  be  maintained,  not  without  reason,  that  the  simple 
cyst-like  form  is  the  common  fundamental  form  from 
which  all  animals  are  developed,  not  merely  in  idea,  but 
historically." 

When  the  barrier  which  it  was  formerly  thought 
necessary  to  erect  between  asexual  multiplication  and 
multiplication  caused  by  fecundation  had  been  recog- 
nized as  non-existent,  and  it  was  perceived  that  all 
development  amounts  to  the  multiplication  and  meta- 
morphosis of  the  primitive  germ  or  egg-cell,  the  cell 
was  necessarily  regarded,  in  the  acceptation  of  the  older 
investigators,  as  the  common  fundamental  form.  But 
although  the  descriptive  history  of  evolution  does  not 
go  back '  to  this  elementary  organism,  and  considers 
even  the  bifurcation  as  merely  a  preparation  for  actual 
development,  at  any  rate  the  earliest  rudimentary  larval 
conditions  of  different  types  may  be  compared  with 
each  other. 

The  discoveries  of  the  last  ten  years  with  reference 
to  this  subject  are  so  numerous,  and  such  striking 
analogies  have  been  advanced,  that  we  must  needs  go 
much  further  than,  at  that  time,  was  possible  for  Von 
Baer.  It  is  not  merely  a  question  of  those  general 
analogies  in  the  segregation  of  tissues  from  an  indiffer- 
ent rudimentary  mass,  but  of  homologies  in  the  distri- 
bution, form,  and  composition  of  the  embryos  and  larvae, 
of  which   the  after  effects  are  of  profound  importance 


EARLIEST   CONDITION   OF   LARVA. 


51 


to  the  later  and  actual  typical  impress.  With  this  object, 
let  us  consider  the  larva  of  a  calcareous  sponge  at  the 
stage  which  Haeckel  has  designated  as  the  Gastrula 
phase. 

The  diaorram  eives  the  section  of  a  larva  of  this 
description,  v.hich  at  this  period  is  nothing  more  than  a 
stomach  provided  with  an  orifice  (fig.  5  ^)  ;  its  wall  con- 


FlG.  5. 


sists  of  two  strata,  or  layers  of  cells.  The  cells  of  the 
external  stratum  are  distinguished  from  those  of  the 
inner  one  by  their  elongated  form,  and  the  possession  of 
filaments  serving  as  organs  of  locomotion.  All  subse- 
quent development  and  differentiation,  certainly  not 
very  important  in  the  sponges,  may  be  traced  to  modi- 
fications of  these  two  membranes  ;  the  external  mem- 
5 


52  THE  DOCTRINE  OF   DESCENT. 

brane  (Ectoderm,  or  Exoderm)  and  the  internal  mem- 
brane (Entoderm).  And  this  phase  of  the  ciHated 
larva,  with  its  twofold  strata,  its  primitive  ventral  cavity 
and  mouth,  recurs  in  the  Coelenterata,  with  slight  varia- 
tions in  the  Echinoderms,  in  some  of  the  Annulosa,  in 
the  Sagitta,  the  Ascidians,  and  the  Lancelet.  From 
the  analogy  of  all  these  animals,  and  especially  of  the 
last,  we  shall  be  able  hereafter  to  derive  important 
inductions. 

But  if  no  weight  be  attached  to  the  presence  of 
these  filaments  of  the  external  layer,  which  is,  moreover, 
justified  by  the  relation  of  the  filament  to  the  cell,  and 
if  it  be  acknowledged  as  the  essential  significance  of 
the  larval  arrangement,  that  from  its  two  laminae  the 
collective  organs  derive  their  origin,  then  to  the  animals 
above  enumerated  must  be  added,  not  only  almost  the 
whole  of  the  Articulata,  but  likewise  the  remainder  of 
the  Vertebrata,  as  in  them,  immediately  after  the  appear- 
ance of  the  primitive  striae,  follows  their  separation  into 
two  cell-layers,  or  membranes.  Respecting  the  deriva- 
tion of  the  third  or  middle  germinal  lamina,  and  the 
share  of  the  two  primitive  laminae  in  its  formation, 
observers  are  not  agreed. 

Only  from  this  point  does  the  development  of  the  great 
animal  groups  take  various  directions,  and  it  is  the  im- 
mortal merit  of  Von  Baer  to  have  fixed  these  types  of 
development,  independently  of  the  fundamental  forms, 
established  by  Cuvier  on  zoological  and  anatomical  con- 
siderations, and  he  thereby  laid  a  far  deeper  foundation 
for  the  existence  of  these  types.  We  will  illustrate  our 
meaning  by  two  examples. 

When   the   ovum  of  the  articulate  animal   has  sur- 


TYPE  OF   DEVELOPMENT  OF  ARTICULATA. 


53 


rounded  itself  with  a  germinal  membrane,  a  portion  of  it 
thickens  into  a  long  germinal  stria,  resembling  an  elon- 
gated ellipse.  This  is  the  rudiment  of  the  ventral  side  of 
the  future  animal.  A  groove  then  divides  it  into  the  two 
germinal  laminae,  and  transverse  striae  next  make  their 
appearance,  the  indications  of  the  so-called  primordial 
segments.  The  symmetrical  disposition  of  the  organs, 
and  the  integration  of  the  body  out 
of  consecutive  segments,  is  herewith 
initiated.  All  further  development 
emanates  from  these  primordial  seg- 
ments, which  are  the  standard  of  the 
'Annelids  or  higher  Vermes  ;  while  in 
the  Articulata,  projections  and  ap- 
pendages of  these  segments  develop 
into  feelers,  manducatory  apparatus 
and  legs,  and  by  their  heterogeneous 
integration  in  the  regions  of  the 
head,  and  of  the  middle  and  posterior 
portions  of  the  body,  give  rise  to  the 
vast  variety  within  the  type.  In  each 
particular  case  we  see  what  is  special 
emanate  from  what  is  more  homogeneous  and  undiffer- 
entiated, and  this  is  likewise  corroborated  by  the  more 
advanced  phase  portrayed  in  the  diagram  (fig.  6).  It 
represents  the  embryo  of  the  great  black-beetle  (Hydro- 
philus  piceus)  on  its  ventral  side.  The  antennae  (/),  the 
three  pair  of  oral  appendages  (;;/),  and  the  three  pair  of 
legs,  are  as  yet  little  distinguished.  In  the  further  course 
of  development,  the  lateral  portions  grow  towards  the 
back,  in  the  centre  of  which  they  finally  meet.  As 
compared  with  the  Vertebrata,   it  may  hence  be  said 


Fig.  6. 


54  THE  DOCTRINE  OF   DESCENT. 

that  the  Articulata  have  their  navel  on  their  backs. 
Conversely,  it  is  the  characteristic  of  the  evolutionary- 
type  of  the  Vertebrata  that  the  position  of  the  germ 
corresponds  with  the  dorsal  side  of  the  animal.  The 
formation  of  the  dorsal  groove,  which  subsequently 
closes  to  form  the  canal  of  the  spinal  cord,  as  it  is 
gradually  enveloped  in  a  sheath  growing  from  below, 
is  followed  by  the  formation  of  transverse  plates,  the 
pre-vertebral  plates.  The  side  plates  lying  outside  of 
these  grow  towards  the  ventral  side,  and  finally  merge 
in  the  navel.  The  position  of  the  actual  vertebral 
column,  consisting  of  separate  vertebrae,  is  always 
originally  occupied  by  a  cartilaginous  band,  the  noto- 
chord  (chorda  dorsalis),  and,  as  from  this  axis,  the  germi- 
nal matter  transforms  itself  into  a  tube  above  as  well  as 
below, — into  the  spinal  marrow  with  its  sheath,  and  the 
ventral  cavity  with  the  intestinal  canal, — Von  Baer  con- 
sidered this  mode  of  development  as  bi-symmetrical. 
The  development  of  the  Articulata  he  regards  as  simply 
symmetrical,  and  the  development  of  the  Molluscs 
he  designated  as  massive.  The  justification  of  this  is 
that  the  elongation  produced  by  segmentation  and  the 
repetition  of  similar  parts  and  sections  of  the  body 
implicit  in  segmentation  generally, — the  metameric  for- 
mation, as  it  is  termed  by  Haeckel, — is  totally  foreign  to 
the  Molluscs. 

We  must  now  again  repeat,  that  somewhat  extensive 
observations  of  the  evolutionary  forms  of  different  ani- 
mals lead  at  once  to  the  belief  that  the  embryos  and 
evolutionary  phases  of  higher  animals  are  transiently 
more  closely  related  to  the  complete  and  definitive  con- 
ditions of  the  lower  animal-forms,  at  least  of  the  same 


SYSTEMATIC  DEVELOPMENT.  55 

family ;  whence  arose  the  fixed  idea  that  the  embryo  of 
the  higher  animals  passes  through  the  forms  of  the  lower 
animals.  When  natural  philosophy,  more  especially  in 
Germany,  had  elaborated  this  doctrine  in  a  rather  fan- 
tastical manner,  and  had  proclaimed  that  Man  was  the 
sum  of  all  animals,  in  structure,  as  well  as  in  develop- 
ment, "  the  doctrine,"  says  Von  Baer,  "of  the  uniformity 
of  individual  metamorphosis  with  the  vague  metamor- 
phoses of  the  whole  animal  kingdom  necessarily  acquired 
great  weight,  when,  by  Rathke's  brilliant  discovery,  ger- 
minal fissures  were  demonstrated  in  the  embryos  of 
mammals  and  of  birds,  and  the  appropriate  vessels 
were  soon  aftervv^ards  actually  revealed." 

The  exaggerations  and  false  inferences  drawn  from 
general  analogies,  and  the  vague  ideas  of  types  hover- 
ing above  the  whole,  and  regulating  individual  develop- 
ment, were  wittily  chastised  by  Von  Baer. 

"  To  convince  ourselves  that  a  doubt  as  to  this  doctrine 
is  not  utterly  groundless,  let  us  imagine  that  the  bird.s 
had  studied  the  history  of  their  development,  and  that 
it  was  they  who  now  investigated  the  structure  of  the 
mature  mammal  and  of  man.  Might  not  their  physio- 
logical manuals  teach  as  follows  i* — *  These  quadrupeds 
and  bipeds  have  much  embryonic  resemblance,  for  their 
cranial  bones  are  separate ;  like  ourselves  during  the 
first  four  or  five  days  of  hatching,  they  are  without 
a  beak  ;  their  extremities  are  tolerably  like  each  other, 
as  are  ours  for  about  the  same  time ;  not  a  single  true 
feather  is  to  be  found  on  their  bodies,  only  thin  feather- 
shafts,  so  that,  even  in  the  nest,  we  are  more  advanced 
than  they  ever  become ;  their  bones  are  not  very  hard, 
and  like  ours,  in  our  youth,  contain  no  air  at  all ;  they 


56 


THE   DOCTRINE   OF   DESCENT. 


are  utterly  destitute  of  air-sacs,  and  their  lungs,  like 
ours  in  early  infancy,  are  not  full-grown ;  a  crop  is  com- 
pletely wanting;  gullet  and  gizzard  are,  more  or  less, 
merged  in  a  sac,  all  conditions  very  transitory  in  us, 
and,  in  most,  the  nails  are  awkwardly  broad,  as  with  us 
before  breaking  the  shell  ;  the  bats,  which  appear  the 
most  perfect,  are  alone  able  to  fly ;  not  the  others.  And 
these  mammals  which,  so  long  after  birth,  are  unable  to 
find  their  own  food,  and  never  rise  from  the  ground, 
fancy  themselves  more  highly  organised  than  we  ? '  " 


KlG.   7. 


Nevertheless,  there  remains  the  fact  of  the  parallelism 
of  individual  development  with  the  systematic  series  to 
which  the  individual  belongs  ;  and,  among  thousands-  of 
examples,  we  will  select  some  of  the  most  accessible  and 
convincing.  Polypes  have  always  been  placed  systemati- 
cally below  the  Medusae;  in  the  development  of  many 


SYSTEMATIC  DEVELOPMENT.  S7 

Medusae  (co  np.  Fig.  3,  p.  43),  a  polype-like  condition  is 
interposed.  The  crinoid  (Comatula),  very  common  in 
the  Mediterranean,  is  in  its  mature  condition  freely 
movable.  This  definitive  development  is,  however,  pre- 
ceded by  a  sessile  stage  (Fig.  7),  during  which  the 
body  is  attached  to  a  stalk.  During  the  larval  period 
the  animal  resembles  the  permanently  sessile  genera, 
which,  by  all  systematic  rules,  and  by  their  geological 
position,  occupy  a  lower  rank  in  the  series  of  echino- 
derms.  The  crabs,  or  anourous  Crustacea,  are  raised  by 
sundry  characteristics  above  their  long-tailed  congeners, 
among  which  is  the  fresh-water  crayfish.  In  the  course 
of  development  they  pass  through  the  long-tailed  stage, 
as  is  shown  in  the  larva  (Fig.  8).  It  is  by  the  abor- 
tion of  the  tail,  which  is  employed  by  the  long-tailed 
species  as  a  natatory  organ,  that  they  become  more 
fitted  for  running,  and  some  of  them  for  terrestrial  life, 
as  they  are,  in  a  measure,  released  from  a  burden. 

One  of  the  systematic  series  included  in  the  Vertebrata, 
leads  through  the  reptiles  to  the  birds.  Now,  if,  in  the 
physiological  reflections  which  Von  Baer  put  into  their 
beaks,  the  birds,  as  will  appear  later,  were  mistaken  in 
boasting  of  their  feathery  garb  in  contrast  to  mammals 
and  to  man,  they  have,  nevertheless,  carried  it  a  stage 
further  than  the  reptiles,  for  the  scale  is  the  embryonic 
rudiment  of  the  feather.  Likewise,  the  tarso-meta- 
tarsal  joint  of  the  embryonic  bird,  with  v/hich  we  are 
already  conversant  (p.  9),  and  which  is  distinguished 
from  the  ankle-joint  of  mammals  and  of  man,  by  its 
lying  not  between  the  leg  and  the  tarsus,  but  in  the 
tarsus  itself,  remains,  as  a  definitive  condition  in  the 
reptile,  in  the  embryonic  condition  which  in  the  bird  it 


58  THE  DOCTRINE  OF   DESCENT. 

rapidly  passes  through.  Although  mammals  are  never 
actual  fish,  there  is  much  that  is  fish-like  in  the  em- 
bryonic phases  of  their  organs ;  the  embryonic  fissures 
in  the  thorax  correspond  with  the  germinal  branchial 
fissures;  the  formation  of  the  brain  may  be  traced  to 
tho  complete  brain  of  the  lampreys  and  the  sharks,  &c. 

In  order  to  refute  the  doctrine  that  the  embryo  passes 
through  the  whole  animal  kingdom,  Von  Baer  was  con- 
tent to  prove  that  it  never  changes  from  one  type  to 
another.  He  repudiated  the  other,  and  more  probable 
part  of  this  theory,  that  is,  that,  at  least  within  the  types, 
the  higher  groups,  in  their  embryonic  phases,  repeated 
the  permanent  forms  of  the  lower  ones,  by  terming  it  a 
question  of  mere  analogies.  The  embryo,  as  it  is  gradually 
perfected  by  progressive  histological  and  morphological 
differentiation,  necessarily  accords,  in  this  t-espcct,  with 
less  developed  animals  in  proportion  to  its  youth.  "  It 
is,  therefore,  very  natural  that  the  embryo  of  the  mammal 
should  be  more  like  that  of  the  fish,  than  the  embryo  of 
the  fish  is  like  the  mammal.  Now,  if  the  fish  be  regarded 
merely  as  a  less  perfect  mammal  (and  this  is  an  un- 
founded hypothesis),  the  mammal  must  be  considered 
as  a  more  highly  developed  fish  ;  and,  in  that  case,  it  is 
quite  logical  to  say  that  the  embryo  of  the  vertebrate 
animal  is  originally  a  fish."  *" 

VVe  have  been  somewhat  faithless  to  our  intention  of 
confining  ourselves  in  this  chapter  to  facts  only.  The 
facts  are  too  apt  to  provoke  reflections,  and  we  have, 
moreover,  repeated  these  reflections  merely  as  historical 
facts  ;  we  must  now  inquire  whether  they  are  really 
capable  of  satisfying  us.  I  think  not.  It  is  by  no 
means  a  merely  histological  and  morphological  differen- 


ABORTIVE  ORGANS.  59 

tiatlon  which  causes  the  resemblance  of  the  higher  in- 
complt.f.e,  to  the  lower  complete  forms.  To  limit  our- 
selves to  one  example:  it  is  quite  incomprehensible 
why  fhe  ear-bones  of  the  mammal  should  be  developed, 
by  the  circuitous  process  of  the  formation  of  germinal 
fissures,  if  it  were  a  mere  question  of  histological  and 
morphological  differentiation.  This  explanation  fails 
also  with  regard  to  the  whole  class  of  the  phenomena 
of  purposeless  and  abortive  organs,  and,  finally,  the 
"evoluttcnary  type"  itself  as  it  rules  the  groups  and 
regulates  individual  development,  still  remains  without 
an  explanation. 


6g  the  doctrine  of  descent. 


IV. 

The  Animal  World  in  its  Historical  and  PaLieontolo^ical  Development. 

It  is  so  easy  to  observe  that  the  earth's  crust,  from  the 
deepest  valleys  to  the  highest  mountain  top  contains 
innumerable  animal  remains,  that  even  antiquity  could 
not  fail  to  notice  it.  But  some  two  thousand  years 
passed  by  before  a  correct  knowledge  was  attained  of 
the  relations  of  these  remains  to  the  present  world. 
Some  thought  they  were  sports  of  nature,  products  of 
creative  power  leading  to  no  special  object,  but  in  a 
certain  measure  to  be  regarded  as  exercises  prelimi- 
nary to  the  actual  creation  of  life  ;  others  considered 
the  fossils  as  remains  of  living  creatures,  indeed,  but 
of  such  as  still  existed,  and  which  had  been  destroyed 
by  overflows  and  subsequent  withdrawals  of  the  sea. 
The  legend  of  the  universal  deluge,  especially,  derived 
great  support  from  this  second  opinion.  Only  when, 
ft  the  end  of  last  century,  the  stratification  of  the  earth's 
crust  was  revealed  to  science,  after  the  outlines  of  a 
history  of  the  solar  system  and  of  a  special  history 
of  the  earth  or  geology  had  been  indicated  by  Kant 
and  Laplace,  only  then  arose  the  possibility  and  neces- 
sity of  a  real  palaeontology,  or  knowledge  of  pre- 
historic life.  At  the  beginning  of  this  century  it  was 
discovered  that  the  fossils  corresponding  with  the  stra- 


GEOLOGICAL  FORMATIONS.  6 1 

tification  of  the  earth's  crust  follow  each  other  in  regular 
sequence,  and  that  in  this  sequence  they  differ  from  the 
present  creation,  as  they  do  from  each  other. 

We  must  make  ourselves  acquainted  with  the  order  of 
succession  of  these  strata.  They  are  the  shelves  in 
which  the  vegetable  and  animal  remains  lie  stored.  To 
arrange  them  was  certainly  possible  only  by  taking  the 
organisms  which  they  contained  as  guides  or  clues. 
We,  however,  shall  take  this  arrangement  as  our  data, 
and,  with  the  object  we  have  in  view,  we  shall  naturally 
consider  only  those  strata  and  rocks  in  which  fossils — 
using  this  word  in  its  widest  interpretation — are  or  might 
be  contained,  those,  namely,  which  are  proved  to  be 
sedimentar}^  i.e.  aqueous  deposits.  Our  information  is 
limited  to  a  great  part  of  Europe,  numerous  districts  of 
America,  and  scattered  points  of  the  rest  of  the  world. 

The  following  table  gives  the  the  arrangement  of  the 
sedimentary  strata  from  above  downwards  : — 

1.  Alluvium. 

2.  Diluvium. 

3.  Tertiary  formation. 

Pliocene. 
Miocene. 
Eocene. 

4.  Cretaceous  formation. 

of  English 


Sinon.  =     White  CTiaTTc  and  Clmlk  ^Ta^l 

Turon.  =     Part  of  the  Chalk  Marl 

Kinoman.     =     Upper  Greensand 

Gault 

Neocoman  (Wealden). 
5.  Jurassic  formation  or  Oolite. 
UpiJer  White  Jura  (Malm). 
Middle  Brown  Jura  (Dogger), 
Lower  Black  Jura  (Lias). 


Series. 
See  p.  307  (^i 
Page's  Ad- 
vanced Text 

Book, 


02  THE   DOCTRINE  OF   DESCENT. 

6.  Tri.issic  formalion  or  New  Red  Sandstone. 

Keuper  or  Variegated  Marls. 

Muschelkalk. 

Variegated  Sandstone. 

7.  Permian  formation  or  Dyas 

Zechstein  (Magnesian  Limestone  or  Dolomitic  Conglomerate). 

Rothliegendes  or  Red  Conglomerate. 
E.  Carboniferous  formation. 

Coal  Measures. 

Millstone  Grit. 

Mountain  Limestone. 
9.  Devonian  formation. 
to.  Silurian  formation. 

11.  Cambrian  formation. 

12.  Laurentian  formation. 

Although  we  are  not  writing  on  geology,  a  short 
explanation  of  these  strata  will  be  requisite,  as  their 
mutual  relations  also  throw  light  on  the  nature  and 
distribution  of  the  contemporaneous  organisms.  All 
displacements  of  earth  which  we  now  see  occurring  by 
means  of  rain,  rivers,  sea  and  other  natural  forces 
which  have  taken  place  in  historic  times,  in  short,  in 
the  so-called  Present,  such  as  the  great  delta  deposits, 
and  the  moraine  formations  of  our  glaciers,  are  ascribed 
to  the  Alliivitim. 

It  was  formerly  supposed  that  its  limits  might  be  dis- 
tinguished from  the  Dihrumm  by  the  appearance  of 
man,  but  as  it  is  now,  and  always  has  been  impossible 
to  affirm  anything  positive  respecting  that  epoch,  and 
as,  although  a  portion  of  the  organisms  of  which  the 
remains  occur  in  the  Diluvial  strata  is  extinct,  much 
more  still  exists,  these*  two  formations  are  inseparably 
intermingled. 

To  the  Diluvium  belong  the  vast  mud  deposits  of 
the  great  rivers,  alternating  with  sand  banks,  the  clay 
and  loess  formations  caused  by  the  removal  of  the  soil 


TERTIARY  FORMATION — CHALK.  6^ 

by  the  drainage  of  the  glaciers  and  the  floods  of  running 
water,  which  at  one  time  increased  periodically  to  a 
degree  truly  colossal.  The  diluvial  period,  as  it  seems, 
includes,  both  in  Europe  and  America,  a  repeated  glaci- 
fication  of  countries  and  vast  portions  of  the  world,  of 
which  the  present  state  of  Greenland  may  now  give 
some  idea. 

The  period  of  the  series  of  strata,  comprised  under 
the  name  of  the  tertiary  formation,  may  be  regarded 
as  that  during  w^hich,  at  least,  the  skeleton  of  the  pre- 
sent continents  finally  attained  its  integral  configuration. 
Within  its  limits  fall  the  erection  and  upheaval  of  the 
great  mountain  chains,  the  Cordilleras,  Alps,  Himalayas, 
and  others  ;  the  outlines  of  the  continents  were,  mean- 
while, in  constant  movement.  This  phenomenon,  how- 
ever, persists  throughout  all  formations,  and,  as  the 
geological  characteristic  of  the  tertiary  formation,  more 
stress  should  be  laid  on  the  separation  of  the  earth's 
surface  into  climatic  zones,  approximating  to  the  zones 
of  the  present  age.  The  names  of  the  subdivisions  are 
intended  to  indicate  the  relation  of  the  animals  then 
living  to  those  of  our  world,  as  it  was  supposed  that  in 
the  eocene  the  first  animals  identical  with  present 
species  were  to  be  found,  more  in  the  miocene,  and,  yet 
more,  in  the  pliocene. 

To  the  chalk  formation  belong  rocks  of  very  various 
kinds,  which  can  be  reduced  to  one  great  geological 
period  by  means  of  their  contents.  If  the  quartzose 
sandstone  of  Saxon  Switzerland  represents  this  forma- 
tion in  the  centre  of  Germany,  it  is  from  the  white  chalk 
of  England  and  Northern  France  that  it  took  its  name. 
In  America,  the  sandstone  has  been  in  a  great  measure 


64  THE  DOCTRINE  OF  DESCENT. 

ground  down  into  sand,  and  in  other  places  the  strata 
are  purely  chalky  or  marly.  But  the  vagueness  of  the 
limitations  of  strata  in  situation,  and  still  more  in  time, 
may  be  estimated  by  the  fact  that  we  are  fully  justi- 
fied in  speaking  of  the  chalk  formation  now  going  on, 
as  is  shown  by  the  investigations  of  Carpenter  and 
W.  Thompson  on  the  constitution  of  the  deep  sea- 
bottom  of  the  Atlantic.  To  the  early  chalk  period 
belongs  a  great  fresh-water  deposit,  and  likewise  the 
Wealden,  a  formation  of  peat  and  bog  occasioned  by 
upheavals,  which  contains  a  number  of  remains  of  fresh- 
water and  terrestrial  animals,  besides  a  peculiar  sort  of 
coal. 

The  oolitic  strata  appear  more  definite,  mostly  lying 
regularly  over  each  other  in  distinct  deposits,  more  rarely, 
as  in  the  Alps,  raised  up  by  later  dislocations.  The  rocks 
themselves,  betray  that  the  depositions  took  place  in 
wide  seas,  for  the  most  part  calm  or  deep,  and  this  is 
rendered  a  certainty  by  the  scanty  vegetal  remains  and 
the  far  more  abundant  animal  remains  which  they  con- 
tain. In  the  apparently  very  sharp  limitation  of  the 
oolitic  formation,  both  above  and  below,  the  older  geo- 
logy found  a  main  prop  for  the  assertion,  that  compara- 
tively quiet  periods  of  long  duration  alternated  with 
catastrophes  destroying  and  re-creating  everything.  To 
avoid  any  misapprehension  we  must,  however,  add  that 
the  oolitic  period  already  possessed  vast  and  highly 
integrated  continents,  as  it  will  likewise  be  seen  that 
during  this  era  the  higher  terrestrial  animals  made 
their  appearance. 

The  characters  shown  by  the  three  great  divisions 
of  the  triassic  formation  are  very  various,  especially  as 


TRIAS — COAL.  65 

ih'cy  are  developed  in  Germany.  The  German  portion, 
judging  by  its  influxes,  must  be  regarded  as  a  forma- 
tion of  strands  and  bays ;  its  more  highly  integrated 
equivalent  in  the  Alps  as  a  huf^e  oceanic  deposit.  The 
Muschelkalk  (which  is  missing  in  England),  with  its 
layers  of  rock  salt  and  rich  remains  of  oceanic  organisms, 
is  likewise  a  marine  formation.  Of  the  origin  of  the 
stratified  variegated  sandstone,  so-called  from  its  varied 
colouring,  with  its  clays,  marls,  and  frequent  vast  enclo- 
sures of  gypsum,  we  obtain  some  idea  from  our  present 
formations  of  sandy  shores  and  dunes.  Like  these,  the 
deposition  of  the  variegated  sandstone  afforded  but 
scanty  opportunities  of  enclosing  animal  and  vegetal 
remains,  but  very  notable  footprints  have  been  preserved, 
such  as  might  now  be  formed  and  preserved,  if  the 
marks  imprinted  on  the  damp  sand  were  filled  up  with 
fine  clayey  particles  torn  by  a  storm  from  some  adjacent 
shore,  and  subdivided  in  the  sea. 

As  the  diversified  appearance  of  the  superimposed 
planes  of  antediluvian  plants  and  animals  of  course 
depends  essentially  on  the  nature  of  their  former  abodes, 
and  as  the  nature  of  the  individual  districts  of  each 
plane  must  then,  as  now,  have  influenced  the  character 
of  the  organisms  by  which  it  was  inhabited,  we  will 
indicate  the  causes  which  thus  affect  life  in  its  form  and 
manifold  variety.  In  order  to  complete  our  view  of  the 
origin  of  the  Earth's  crust,  and  the  dependence  of  the 
organic  on  the  configuration  of  the  inorganic  world,  we 
will  leave  a  geologist,  Credner,  to  describe  the  relations 
of  the  dyassic  and  carboniferous  formations  :  "  In  regions 
where  the  carboniferous  (coal)  formation  is  typically 
developed,  it  consists  of  a  series  of  stratifications,  the 


66  THE   DOCTRINE   OF  DESCENT. 

lower  one  chalky  (mountain  limestone),  the  middle  git.-? 
conglomerated  or  arenaceous  (millstone  grit),  and  the 
upper  one  carboniferous  (coal  measures);  hence  a  marine, 
a  littoral  and  a  marsh  or  fresh-water  formation.  It  is 
easy  to  imagine  the  cause  of  this  phenomenon ;  it  de- 
pends on  the  secular  elevation  of  the  primaeval  sea 
bottom,  on  which  was  deposited  first  the  marine  moun- 
tain limestone  ;  secondly,  as  it  rose  to  the  surface,  the 
shingle  and  coarse  sand  of  the  shore ;  and  finally,  on 
persistent  elevation,  the  products  of  marshes,  lagunes, 
and  estuaries.  If  it  now  happened  that  some  portions 
of  the  infant  continent  covered  with  the  latter  (that  is 
to  say,  with  the  productive  carboniferous  strata),  were 
seized  with  an  opposite  movement,  and  therefore  sank, 
there  would  be  deposited  on  the  surface  now  again 
gradually  becoming  the  bed  of  the  sea,  precisely  similar 
forms,  only  in  inverse  order  to  that  which  occurred 
during  the  period  of  elevation. 

And,  in  fact,  this  phenomenon  is  exhibited  by  those 
portions  of  the  earth's  surface  which  shortly  after  the 
formation  of  the  coal  measures  again  sank  below  the 
sea.  In  Germany  and  England  the  productive  coal 
measures  are  followed  by  a  sandstone  and  conglomerate, 
therefore  a  littoral  formation,  exactly  like  the  quartzose 
sandstone  and  millstone  grit  which  underlies  them;  and 
above  this  a  limestone,  dolomite  and  gypsum  formation, 
corresponding  to  the  mountain  limestone,  the  lowest 
member  of  the  carboniferous  system.  On  account  of 
the  division  which  is  displayed  in  profound  palaeon- 
tological  and  petrographical  diversities,  the  formation 
thus  developed  and  composed  is  designated  as  the 
Dyas.      The  separate  phases   of  this   cycle  of  occur- 


DEVONIAN  AND  SILURIAN   STRATA. 


67 


fences,  by  which  tlie  carboniferous  and  Dyassic  forma- 
tions were  evolved,  are  accordingly  (reading  from  above 
downwards) : 


5.  Deep  Sea. 

Marine 
forms. 

Mountain 
Limestone. 

Marine 
animals. 

4  Subsidence 
beneath  the 
Sea. 

Littoral 
forr.is. 

Conglome- 
rate and 
Sandstone. 

3.  Quiescence. 

Freshwater 

and 

Marsh  forms. 

Coal 
measures. 

Terrestrial 
plants. 

•s.    Upheaval 
above  the 
Sea. 

Littoral 
forms. 

Conglome- 
rate and 
Sandstone. 

I.   Deep  Sea. 

Marine 
forms. 

Mountain 
Limestone. 

Marine 
animals. 

Magnesian 
Limestone. 

Red  Sand- 
stone. 


Coal  mea- 
sures, Red 
Sandstone, 
Coal  fields.  { 

Millstone 
grit. 


Carbonife- 
rous Lime- 
stone. 


Dyas. 


Carbonife- 
^  rous  forma- 
tion. 


From  this  account  it  is  also  manifest  that  in  cases  of 
incomplete  elevation,  such  as  took  place  in  North 
America,  the  formation  of  the  middle  period  is  either 
disturbed  or  totally  omitted,  and  that  it  may  depend  on 
local  causes  and  the  duration  of  the  oscillations  if, 
as  in  the  Russian  Permian  formations,  corresponding  to 
the  German  Dyas,  the  boundaries  of  the  subdivisions 
are  more  or  less  obliterated. 

The  two  series  of  strata  beneath  the  mountain  lime- 
stone, and  reaching  the  depth  of  more  than  3000  and 
6000  metres,  the  Devonian  and  Silurian  formations, 
are  the  lowest,  and  therefore  the  first  which  clearly 
bear  the  mark  of  their  origin  as  marine  deposits.  Both 
6 


68  THE   DOCTRINE  OF   DESCENT. 

groups  were  formerly  comprised  under  the  name  of 
Transition  rocks,  or  Graywacke  formation.  In  them 
also  sandy,  clayey,  and  chalky  rocks  alternate  with  one 
another,  already  exhibiting  modifications  of  a  local 
nature,  from  which,  towards  the  carboniferous  period, 
issued  the  first  beginnings  of  continental  upheaval. 

The  granite,  gneiss  and  slate,  which  as  primary  rocks, 
or  primitive  formations,  originated  before  the  Silurian 
rocks,  are  for  the  most  part  sediments  of  hot  or  very 
warm  primaeval  seas,  which  have  undergone  manifold 
internal  changes  from  pressure  and  heat.  Till  recently, 
they  were  likewise  termed  the  Azoic  group,  as  contain- 
ing no  vestiges  of  life,  when  the  discovery  of  the 
Eozoon  and  its  unlimited  occurrence  in  the  Laurentian 
strata  of  Canada,  proved  that  the  required  conclusion  to 
the  series  had  actually  taken  place. 

With  this  Eozoon  we  begin  the  enumeration  of  the 
antediluvian  animals  from  below  upwards.  The  remains 
of  this  creature  consist  of  a  more  or  less  irregular  system 
of  chambers  with  cretaceous  walls,  of  which  the  interior 
is  filled  with  serpentine  or  pyroxene.  It  was  attempted 
to  deny  the  organic  origin  of  this  cretaceous  testa,  which 
may  best  be  compared  to  the  shells  of  the  Foraminifera. 
But  renewed  researches  have  substantiated  that  although 
in  the  great  mass  of  the  Eozoon  rocks  occurring  in  vast 
strata,  metamorphosis  has  rendered  it  nearly,  if  not 
quite,  impossible  to  recognize  the  true  nature  of  the 
body,  pieces  here  and  there  occur  with  the  chambering 
so  distinctly  marked,  and  a  tubular  structure  peculiar 
I  to  the  Foraminifera,  which  exclude  any  other  interpre- 
tation than  that  of  a  living  being  resembling  the  low 
Foraminifera.     This  is  of  great  significance,  as  the  pro- 


GRAPTOI.ITES — TRILOBITES. 


69 


fusion-  of  life  met  with  in  the  Silurian  and  Devonian 
strata  presupposes  an  immeasurably  long  antecedent 
period  during  which  life  had  already  existed  and  gradu- 
ally increased  to  the  multitudes  of  the  Silurian  era. 
We  discover  in  it  but  scanty  remains  of  marine  plants, 
and  only  marine  animals ;  but  these  are  so  heterogeneous 
and  varied  in  form,  that  they  alone  would  oblige  us  to 
infer  the  existence  of  coasts,  shallow  or  deep  oceanic 
regions,  and  a  number  of  geographical  conditions  on 
which  we  see  the  variety  and  extent  of  animal  life  to  be 
dependent.  Besides  numerous  forms  of 
corals  more  nearly  allied  to  still  exist- 
'ing  families,  we  find  the  quite  peculiar 
group  of  Graptolites  (fig.  9),  which, 
although  not  actual  polypes,  might  be 
ranged  next  to  the  so-called  Medusa- 
polypes,  and  thus  justify  the  inference 
that  preparation  was  being  made  for  the 
appearance  of  the  higher  forms  of  the 
Coelenterata,  the  Medusae. 

The  Articulata  are  represented  by  the 
Trilobites  (fig.  10,  Trilobites  remipes), 
a  crab-like  form  which  recalls  the  pre- 
sent group  of  the  Lamellibranchiata,  but 
has  not  hit  icrto  admitted  of  any  closer  definition,  as 
in  none  of  th:r  many  thousand  specimens  examined, 
of  the  forms  (about  2000)  known  in  the  Silurian  and 
Devonian  strata,  have  the  legs  been  preserved.  In  these 
three-lobed  crabs,  the  head,  trunk,  and  tail  distinctly  ap- 
pear, as  well  as  the  threefold  transverse  division.  The 
two  composite  eyes  already  indicate  a  high  grade  of 
organization.      The   power   of    rolling   themselves    up, 


70 


THE   DOCTRINE   OF   DESCENT. 


which  they  have  in  common  with  several  of  the  crabs 
now  inhabiting  shallow  waters  and  coasts,  and  likewise 
their  general  habit,  allow  us  to  infer  that  they  also  were 
denizens  of  coasts. 

The  Molluscs  were  mainly  represented  by  Brachiopoda 
and  Cephalopoda.     However,  as  Bivalves  and  Gaster- 


opoda were  also  in  existence,  the  appearance  of  this,  the 
most  ancient  molluscous  fauna  known,  differs  from  the 
present  one  only  in  its  numerical  proportions,  and  in  the 


FAUNA  OF   THE   DEVONIAN   PERIOD.  7 1 

circumstance,  certainly  very  important,  that  of  the 
Cephalopoda  the  Nautilus  alone  is  found.  The  Brachio- 
poda  soon  attain  to  their  highest  development,  and  have 
lingered  on  till  now  in  a  greatly  reduced  state.  Among 
the  Conchifera,  the  Dimyariae  take  the  lead  in  the  course 
of  the  later  period ;  and  with  regard  to  the  Gasteropods, 
we  will  merely  observe  that  they  constantly  increase  in 
internal  complexity  and  variety  as  they  approach  more 
recent  periods,  and  that  the  terrestrial  and  fresh-water 
species  are  occasionally  found  in  the  carboniferous 
formation,  though  in  number  and  variety  they  belong 
primarily  to  the  Tertiary  era.  To  the  Cephalopoda  we 
must  return  again.  Of  the  Vertebrata  in  the  Silurian 
strata  we  know  only  the  remains  of  peculiar  Fishes  whose 
kindred  must  be  sought  among  the  sharks  and  rays. 

In  the  period  of  the  Devonian  or  upper  Transition 
rocks,  the  surface  of  the  earth  had  assumed,  at  least  in 
places,  a  more  smiling  appearance.  Here  begins  the 
first  record  of  terrestrial  plants.  As  to  the  character  of 
the  fauna,  the  rapid  decrease  of  the  Trilobites  is  worthy 
of  notice,  and  the  appearance  of  the  important  genus 
of  the  Cephalopoda,  Clymenia,  subsequently  replaced 
by  the  Ammonites.  Above  all,  we  must  note  the 
increased  abundance  of  fish  which  still  form  the  sole 
representatives  of  the  Vertebrata,  and  held  undisputed 
sway  in  the  seas  of  that  period.  Besides  the  sharks,  there 
are  the  mailed  Ganoids.  It  is  true,  the  fish,  the  hinder 
part  of  which  is  here  portrayed  (Fig.  1 1,  Palaeoniscus), 
belongs  only  to  the  upper  Coal  and  Zechstein  formation  ; 
but  it  is  necessary  even  now  to  point  out  the  character- 
istics of  the  true  Ganoids  which  floundered  about  the 
Silurian  seas  in  somewhat  extraordinary  forms.  Agassiz 


72 


THE   DOCTRINE   OF   DESCENT. 


terms  them  Placoids,  from  the  rhombic  scales,  provided 
with  a  layer  of  enamel  highly  favourable  to  preserva- 
tion,  and   covering  the  whole  surface  in  oblique  rows. 


The  vertebral  column,  as  in  the  sharks,  enters  the  upper 
flap  of  the  tail  and  renders  it  strikingly  unsymmetrical. 
The  Ganoids  are,  as  comparative  anatomy  has  proved 
with  certainty,  a  development  of  the  shark-like  fishes,  if 
not  decidedly  of  a  higher  grade.  The  Ganoids,  there- 
fore, presuppose  the  shark. 

The  carboniferous  period  owes  its  name  to  the  enor- 
mous accumulation  occurring  in  its  midst,  of  the 
remains  of  terrestrial  plants,  fern-like  Calamites,  and 
more  especially  of  Sigillaria  and  Lepidodendra,  stand- 
ing between  vascular  Cryptogams  and  Conifers.  They 
formed  tropical  bog-forests,  such  as  Franz  Unger  some 
years  ago  attempted  to  restore  in  an  ingenious  compo- 
sition. In  these  steaming  primaeval  forests,  differing 
from  the  early  beginnings  of  antecedent  periods  by 
their  extent  and  luxuriance,  new  phases  of  animal 
life  become  manifest — scorpions,  myriapods,  and  in- 
sects—in other  words,  air-breathing  Articulata,  and 
likewise  the  first  air-breathing  Vertebrata.     The  latter, 


FAUNA  OF   THE  TRIAS.  73 

the  Chelrotheria,  or  Labyrinthodonta  (colossal  Batra- 
cliians)  possess  pre-eminently  amphibian  characters,  an  J 
exhibit,  for  example,  several  important  characteristics  oi 
the  Batrachian  skull,  whereas  their  skin-covering  recalls 
the  scale-armour  of  the  Saurians.  Thus  we  find  cha- 
racters combined  which  are  subsequently  divided  among 
different  groups.  There  are  also  traces  of  huge  sea-lizards. 
But  here,  and  likewise  in  the  magnesian  limestone  for- 
mation, these  amphibian-like  animals  still  keep  in  the 
background  amid  the  profusion  of  Ganoids,  which  espe- 
cially characterizes  some  of  the  strata  of  the  magnesian 
limestone  formation,  the  Kupferschiefer,  or  cupriferous 
marl  formation.  For  the  sake  of  classification,  the  Zech- 
stein  is  not  unfitly  supposed  to  conclude  a  great  period 
of  organic  development :  the  series  of  formations  from 
the  Silurian  to  the  end  of  the  Zechstein  is  termed  palse- 
azoic  ;  and  those  which  follow,  the  Trias,  Oolite,  and 
Cretaceous  formations,  are  summed  up  as  mesozoic. 

The  Trilobites,  the  mailed  Ganoids,  and  others  have 
now  disappeared,  and  the  enormous  development  of 
reptile  life  stamps  this  middle  period.  The  Trias  as 
yet  possesses  no  true  Teleostei.  The  Labyrinthodonta 
still  predominate;  while  the  Archaeosauros  and  the  Pro- 
terosaurus,  which  had  already  appeared  in  the  Dyas,  are 
replaced  by  more  numerous  forms  approximating  to  the 
true  reptiles.  One  single  discovery  in  the  upper  member 
of  the  Trias — the  teeth  of  a  predatory  marsupial — has 
supplied  us  with  the  most  ancient  traces  of  a  mammal. 
It  might  be  inferred,  even  from  the  petrographic  cha- 
racter of  the  oolitic  strata,  that  this  era  must  have  been, 
on  the  whole,  far  more  favourable  to  the  development  of 
unimal  life  than  the  more  perturbed  Triassic  period,  or 


74  THE   DOCTRINE  OF   DESCENT. 

that  at  least  a  more  copious  preservation  of  organic 
remains  might  be  expected,  for  the  ooHtic  strata  are 
mostly  depositions  which  have  taken  place  without  dis- 
turbance. 

And  so  it  proves.  The  Placoids  and  Ganoids  hitherto 
predominating  in  the  ocean  almost  without  a  foe,  now 
found  overwhelming  enemies  in  the  true  sea-lizards,  or 
Enaliosaurians,  especially  the  Ichthyosaura  and  Plesio- 
saura.  The  head  is  like  a  lizard  or  a  crocodile,  the  ver- 
tebral column  fish-like,  and,  as  Gegenbauer  has  shown, 
the  extremities  also  recall  the  simpler  fins  of  sharks. 
Their  coprolites  likewise  allow  us  to  infer  with  full 
certainty,  a  very  peculiar  construction  of  the  middle 
portion  of  the  intestinal  canal.  They  possessed  a  spiral 
intestine  like  that  of  the  sharks  and  their  congeners. 
These  animals  are  therefore  noteworthy,  not  only  on  ac- 
count of  their  striking  external  appearance  and  the  part 
they  play  in  nature's  household,  but,  like  the  Labyrintho- 
don,  as  intermediate  and  connecting  forms  of  reptiles  and 
of  fish. 

Besides  these  animals,  a  conspicuous  group  of  the 
marine  fauna  is  that  of  the  Ammonites,  which  occur  in 
masses,  and  next  to  the  Nautili  constitute  the  chief 
form  of  the  ancient  Cephalopoda,  the  study  of  which 
has  recently  promised  to  contribute  essentially  to  the 
decision  of  the  most  important  points  in  our  science. 
In  combination  with  them,  the  Belemnites  abound  with 
their  multitudinous  species,  originating  in  the  Trias. 
They  are  proved  to  be  the  predecessors  of  dibranchiate 
Cephalopoda,  which  now  predominate.  On  the  chalk 
plains  of  Eichstadt  and  Solnhofen,  belonging  to  the 
White   Jura,    are   also   preserved    impressions,   resembling 


FAUNA  OF  THE  OOLITES.  75 

drawings,  of  Medusae,  which  show  that  even  at  that  time 
this  class  had  reached  the  state  in  which  it  still  exists. 

The  terrestrial  fauna  of  the  Jurassic  period  is  like- 
wise enriched  by  new  forms  and  groups.  We  find  the 
first  true  crocodiles,  tortoises,  and  the  most  remarkable 
variation  of  the  Sauroid  type,  the  winged  lizard  or 
Pterodactyl.  It  is  evident  from  their  well-preserved 
skeletons  that  the  wing  membrane  was  stretched,  as  in 
the  bat,  between  the  posterior  and  anterior  extremities. 
Behind,  it  extended  to  the  foot,  while  in  front,  it  obtained 
a  corresponding  addition  by  the  elongation  of  the  little 
finger.  A  first  and  only  bird  has  likewise  been  found 
in  the  well-known  resting-places  of  the  Pterodactyls,  in 
the  lithographic  slates  of  Solnhofen  in  Bavaria  (Archae- 
opterix  lithographica).  The  most  remarkable  peculiarity 
of  this  bird,  recognizable  by  the  most  minute  impression 
of  its  feathers,  is  the  long  tail,  bordered  by  two  rows  of 
rigid  feathers.  The  head  is  unfortunately  crushed  beyond 
recognition.  The  inferior  order  of  Mammals  already 
mentioned,  the  Marsupials,  were  also  present,  as  is  shown 
by  the  enclosures  of  the  middle  Oolite  of  England  and 
the  upper  Oolite  of  the  Purbeck  strata. 

The  ornithic  animals  of  the  chalk  are  more  remark- 
able intermediate  forms  than  the  Archaeopteryx,  and 
these  by  the  hour-glass-shaped  centres  of  the  vertebrae 
are  directly  connected  with  the  sea-lizards  of  the  Jura; 
they  also  possess  teeth  ;  this  may,  however,  be  the  case 
with  the  Archaeopteryx  also.  We  shall  return  later  to 
these  creatures,  which  fill  up  a  void  hitherto  very  con- 
spicuous. During  this  new  period  the  Ammonites  were 
most  abundant,  and  then  became  extinct,  after  going 
through  a  stage  of  degenerate  forms  which  may  be  ob- 


76  THE  DOCTRINE   OF  DESCENT. 

served  in  the  Turrilites,  Scaphites,  Baculites,  and  various 
others.  The  prime  of  the  great  sea-lizards  is  also  past,  but 
the  marshes  of  the  Wealden  period  harboured  new  forms 
of  colossal  land-lizards.  The  long-tailed  cray-fishes  are 
joined  by  the  true  crabs,  the  most  highly  developed 
forms  of  the  class.  In  the  Oolite  and  Chalk  also  occur 
the  chief  of  the  sea-urchin-like  Echinodermata.  As  yet 
we  have  not  mentioned  the  class  of  Echinodermata,  in 
order  that  we  might  here  point  out  in  conjunction  several 
of  the  more  important  phases  of  their  geological  occur- 
rence. Desor,*  a  distinguished  judge  of  this  class,  has 
lately  examined  how  in  this  large  group  of  Echinidas 
the  progress  of  organization  is  gradually  manifested,  on 
which  occasion  he  was  induced  to  make  some  general 
reflections  on  the  principle  of  progressive  development, 
as  applied  to  the  Echinodermata,  probably  known  to  all 
our  readers  in  their  representatives  the  star-fish  and  sea- 
urchins.  If  articulate,  as  well  as  vertebrate,  animals  attain 
a  higher  grade  of  development  by  the  differentiation  of  the 
consecutive  segments  of  the  body,  the  superior  unity,  and 
therewith  higher  perfection,  of  the  Echinoderm's  body  is 
evinced  when  the  rays,  or  so-called  antimera,  give  way  to 
the  unity  of  the  wdiole. 

The  more  distinct  these  elements  are,  that  is  to  say,  the 
more  independent  they  remain,  the  lower  is,  not  only  the 
articulate  animal,  but  also  the  Echinoderm.  Accord- 
ingly, the  star-fish,  and  to  some  extent  the  feather-stars, 
stone -lilies,  or  crinoids,  occupy  the  lowest  rank.  But 
here,  unluckily,  palaeontological  evidence  again  aban- 
dons us.  Only  so  much  is  certain,  that  in  the  older 
fossiliferous    strata   both    divisions   are    abundantly  repre- 

*  Eu'letin  de  la  Societe  des  Sciences  Naturelles  de  Neufchatel,  IX.  2. 


TRANSFORMATIONS   OF  THE   ECHINiE.  TJ 

seated.  A  highly  remarkable  and  important  interme- 
diate form  is  also  known,  found  in  the  upper  Silurian 
strata  of  Dudley  (Eucladia  Johnsoni),  the  more  impor- 
tant as  but  few  transitional  forms  between  one  order 
and  another  have  been  hitherto  discovered.  The  rela- 
tion of  the  star-fish  to  the  sea-urchins  is  still  indistinct. 
On  the  other  hand,  the  bridge  from  the  stone-lilies  to 
the  sea-urchins  is  tolerably  apparent.  The  true  Crinoids 
are  sessile,  and  with  them  are  connected,  in  the  carbon- 
iferous formation,  the  no  longer  sessile  Cystoids  and 
Blastoids,  with  which  are  associated  the  Tessellae,  more 
resembling  the  sea-urchins.  Now  the  Dyas  and  Trias 
are  still  poor  in  true  Echini ;  the  Oolite,  on  the  contrary, 
very  rich  ;  and  in  this  great  period  the  extraordinarily 
heterogeneous  transformations  of  the  Echinidae  are  slowly 
accomplished,  and  may  be  traced,  step  by  step,  from  the 
Lias,  the  earliest  oolitic  formation,  to  the  coral  limestone. 
At  first  the  Cidaridae  predominate ;  they  are  joined  in  the 
Oolite  by  the  Echinoconidse  and  Cassidulidse.  A  sharper 
distinction  of  species  is  characteristic  of  the  later  strata  of 
the  Upper  Jura. 

Desor  shows  how  this  development,  accompanied  by 
temporary  quiescence,  is  connected  with  the  nature  of  the 
sea-bottom  at  the  time.  "  The  law  of  progress,"  he  says, 
"  is  displayed  in  the  circumstance  that  it  is  the  lowest  of 
the  Echinae,  the  Regularae  and  Endocyclicae,  which  pri- 
marily appear,  first  in  the  form  of  the  Tessellae,  then  as 
Cidaridse  ;  while  the  most  perfect  Spatangae,  with  the 
most  distinctly  marked  bilateral  form,  make  their  ap- 
pearance last  of  all.  Between  these  extremes  we  find 
a  host  of  genera  and  species  distinguished  from  one 
another  by  mere  shades,  so  that  of  tvro  allied  genera  it  is 


78  THE   DOCTRINE   OF   DESCENT. 

often  difficult,  nay,  impossible,  to  state  which  is  the  more 
perfect.  Progression  is  only  to  be  shown  collectively  ;  in 
the  concrete  case  it  can  rarely  be  demonstrated." 

The  Echinae  still  predominate  in  the  chalk.  Recent 
discoveries  of  analogous  animals,  with  soft  and  still 
flexible  integuments,  confirm  what  was  theoretically  ex- 
tremely probable,  that  from  them  proceeded  the  high- 
est existing  order  of  the  Holothuria  or  Sea-cucumbers ; 
and  thus  the  division  of  Echinoderms  conforms  to  the 
universal  experience  of  the  ascent  from  the  lower  and 
undifferentiated  to  the  higher  forms. 

With  the  Tertiary  period  dawns  the  state  of  things 
now  existing.  Palms  and  arboraceous  plants  charac- 
terize the  vegetation.  The  animal  world  has  likewise 
remained  essentially  the  same  from  the  earliest  sections 
of  the  Tertiary  period  until  now,  as  we  shall  more 
elaborately  set  forth  in  the  chapter  on  Geographical  Dis- 
tribution. In  the  most  ancient  formations  the  Fishes,  in 
the  middle  the  Reptiles,  were  conspicuous  in  the  world 
of  life  as  the  representatives  of  the  highest  development ; 
now  when  the  continents,  not  indeed  without  sundry 
local  oscillations,  are  approximating  to  their  present 
configuration,  the  impress  of  the  Mammalia  becomes 
predominant.  Under  the  influence  of  elevations  and 
depressions,  of  several  glacial  periods,  and  the  more 
sharply  defined  limits  of  the  climatic  zones,  frequent 
displacements  occurred  in  the  vegetal  and  animal  world, 
accompanied  by  differentiation  and  further  develop- 
ment. As  we  have  already  mentioned,  the  course  of  our 
inquiries  will  bring  us  back  to  this  subject. 

At  the  time  when  geologists  believed  in  the  rigid  parti- 
tion of  the  earth's  periods  of  development  and  the  sharply 


GENERAL  CHARACTER  OF  ANTEDILUVIAN  WORLD.  79 

separated  succession  of  the  evidence  in  its  favour,  that  is 
to  say,  of  the  systems  of  stratification,  the  fixed  concep- 
tion of  a  fossil  was,  that  whatever  had  lived  before  the 
appearance  of  man  on  the  threshold  of  the  Alluvial 
period  was  fossil.  It  has  been  proved  that  the  existence 
of  man  is  far  more  ancient ;  that  species  and  races  which 
surrounded  the  cradle  of  mankind  have  become  extinct ; 
hence  that  they,  like  the  Mammoth,  for  example,  are 
fossil  to  us  only,  and  not  to  our  diluvial  forefathers ; 
while  many  other  animal  forms  which  existed  before 
man  have  been  preserved  till  now.  On  the  whole,  from 
the  Tertiary  period  forwards,  the  herbivorous  Mammals 
precede  the  Carnivora.  The  monkeys  appear  only 
shortly  before  man. 

Notwithstanding  many  gaps  in  the  pal?eontological 
record,  the  progress  of  development  is  manifest  in  the 
organic  world,  including  the  vegetal  kingdom.  No  fossil 
animal  controverts  the  system.  On  the  contrary,  the  most 
varied  adjustments  and  accommodations  are  afforded  by 
the  antediluvian  animals.  If,  for  instance,  the  present 
Pachyderms  are  sharply  distinguished  from  the  Rumi- 
nants, an  unbroken  bridge  between  them  is  established  by 
the  extinct  forms.  If  the  present  time  shows  us  only 
single  scattered  genera  of  the  Edentata,  the  Diluvial 
period  exhibits  a  considerable  number  under  far  more 
heterogeneous  forms.  Thus  in  the  types  as  in  the  divi- 
sions of  the  classes,  the  system  advances  from  the  older 
to  the  more  recent  periods ;  while  the  more  ancient  groups 
gradually  increase  and  then  diminish,  as  newer,  more 
perfectly  or  specifically  integrated  forms,  are  interposed. 
The  former  either  vanish  entirely  or  outlast  the  moie 
recent  periods    and  continue  in  scanty  remnants  down 


80  THE  DOCTRINE  OF   DESCENT. 

to  the  present  day.  The  formations  mostly  have  their 
characteristic  organisms,  but  almost  everywhere  the  con- 
necting links  have  been  exhibited.  Everything  conduces 
to  show  that  it  is  a  question  of  evolution,  not  revolution. 
Wherever  there  seems  to  be  a  sudden  break,  the  case  is 
the  same  as  in  the  revolutions  of  human  history,  in  which 
likewise  only  reforms  long-prepared,  and  practically 
necessary,  come  to  a  rapid  issue. 

If  we  sum  up  the  result  of  the  comparison  of  fossil  with 
living  animal  life,  we  are  first  of  all  struck  by  the  accord- 
ance between  the  grades  succeeding  one  another  in  the 
order  of  time,  and  the  members  nowM-anged  side  by  side 
in  the  system.  Secondly,  when  this  is  confirmed,  the 
parallelism  between  the  geological  succession  of  animals 
and  the  grades  of  the  individual  development  of  present 
animals  follows  as  a  matter  of  course.  Agassiz,  in  his 
great  work  on  fossil  fishes,  pointed  out  this  fact  with 
irresistible  force,  and  confirmed  it  by  fresh,  valuable,  and 
convincing  observations  in  his  later  works,  down  to  his 
investigations  as  to  the  development  and  growth  of 
corals.  The  same  examples  which  served  in  the  preced- 
ing chapter  to  illustrate  the  parallelism  of  individual  de- 
velopment with  the  systematic  stages,  may  be  repeated 
here ;  though  many  newer  and  very  striking  instances 
have  been  brought  to  light  by  the  special  researches 
of  the  last  ten  years.  To  express  this  relatiou,  Agassiz 
introduced  the  term  "  embryonic  types,^'  or  "  embryonic 
representatives."  Thus  the  stalked  stone  lilies  are  the 
embryonic  types  of  the  present  genus  Comatula  ;  the 
most  ancient  Echinidae  are  the  embryonic  representatives 
of  the  higher  families  of  the  Clypeastrae  and  Spatangidae  ; 
the  Mastodon,  on  account  of  its   persistent    molar   teeth, 


SO-CALLED  EMBRYONIC  AND  PROPHETIC  TYPES.  8 1 

is  the  embryonic  type  of  the  elephant,  which  only  transi- 
torily possesses  such  teeth.  If  the  term  implies  nothing 
further  than  the  vague  assertion  of  "the  working  of 
the  same  creative  Mind  through  all  times  and  upon  the 
whole  surface  of  the  globe,"  '*  scarcely  any  solution  is 
obtained.  Let  us  rather,  with  Rutimeyer  in  his  admi- 
rable researches  on  fossil  horses,'^  allow  our  attention  to 
be  drawn  by  these  and  similar  facts  "  to  a  close  connec- 
tion between  the  phases  of  development  in  the  individual 
and  in  the  species,"  that  is,  to  a  natural  connection. 

All  who  absolutely  require  a  personal  God  in  the 
current  history  of  creation,  draw  from  these  facts  no 
other  inference  than  that  their  God  had  the  whim  of 
producing  at  first  imperfect  and  subsequently  more  and 
more  perfect  organisms,  and  of  applying  in  the  develop- 
ment of  the  last  reminiscences  of  the  first 

As  worthless  as  the  formula  of  embryonic  t>^pes  is 
another,  invented  by  Agassiz,  for  the  shapes  in  which, 
in  some  fossil  groups,  mechanical  and  physiological 
results  were  imperfectly  obtained,  and  for  which  provi- 
sion is  made  in  later  organisms  by  other  more  adequate 
and  perfect  arrangements.  These  are  his  "prophetic 
types."  The  Pterodactyl  is,  for  example,  supposed 
to  stand  in  this  relation  towards  the  bird.  Does  this 
quibble  aid  in  the  comprehension  of  either  one  or  the 
other  .-*  Is  any  rational  idea  obtained  if,  besides  the 
prophecy  of  the  Pterodactyl,  the  geologically  antece- 
dent insect  is  regarded  as  its  prophet,  or  the  bird  as 
the  forerunner  of  the  bat  ?  There  is  no  sense  at  all 
unless  the  prophet  becomes  the  progenitor,  which  in 
these  cases  cannot  be  supposed. 


82  THE  DOCTRINE  OF  DESCENT. 


V. 

The  Standpoint  of  the  Miraculous,  and  the  Investigation  of  Nature— Creation 
or  Natural  Development— Linnasus—Cuvier—Agassiz— Examination  oi 
the  Idea  of  Species. 

"  I  hear  your  message  well,  it  cannot  wake  my  faith. 
To  faith  is  miracle  her  dearest  child."* 

Having  quoted  these  words  of  Faust,  we  will  proceed 
without  further  digression  to  examine  the  standpoint 
occupied  by  the  Natural  Philosopher  with  regard  to  a 
domain  where  the  sceptre  is  wielded,  not  by  the  lucid 
intellect,  but  by  the  imagination  looking  through  coloured 
glasses ;  not  by  Logic,  but  by  arbitrary  ideas ;  where 
the  laws  of  causality  are  turned  upside  down;  a  domain 
where,  indeed,  many  unquestionably  honourable  men 
still  feel  themselves  at  home,  but  which  at  best  fosters 
only  pious  self-deception,  and  indolence  of  mind. 

We  must  take  up  a  decided  position  without  regard 
to  consequences,  as  after  the  discussion  of  the  actual 
record  of  the  animal  world  in  its  three  aspects, 
namely,  its  present  tenantry  of  complete  forms,  the 
evolution  of  the  individuals,  and  the  historical  suc- 
cession during  the  earlier  periods  of  the  earth's  forma- 
tion,— after  this  superficial  work  of  registration  and 
enrolment,  the  actual  study  of  our  subject  must  begin. 

•  "  Die  Botschaft  hor'ich  wohl,  allein  mir  fehlt  der  Glaube. 
Das  Wunder  ist  des  Glaubens  liebstes  Kind." 


LINNiEUS.  83 

This  is,  however,  the  case  only  with  those  to  whom  the 
miracle  of  creation  is  absolutely  without  existence ; 
whereas  an  observer,  who  regards  any  miracle,  how- 
ever slight,  or  any  sort  of  disturbance  of  the  order  of 
nature,  as  possible,  must  deem  his  science  of  Biology 
complete  with  the  erudition  formerly  propounded,  and 
subsequently  extended  by  countless  items  of  special  in- 
formation. We  cannot  therefore  do  otherwise  than  give 
to  Goethe's  maxim,  "  Belief  is  not  the  beginning,  but  the 
end  of  all  knowledge,"  the  interpretation  that  belief  is 
incompatible  with  knowledge,  and  that  hence  belief  in  a 
creation  of  life  is  incompatible  with  the  investigation 
of  it. 

But  if  Life  did  not  originate  in  an  incomprehensible 
manner,  it  must  have  been  developed.  Many  decades 
elapsed  before  this  idea  with  its  consequences  could  be 
stated  ;  and  in  order  to  comprehend  the  obstinacy 
with  which  the  contrary  was  maintained,  and  a  circle  of 
opinions  allowed  to  take  root,  against  which  modern 
Biology  alone  has  waged  a  successful  war,  it  is  necessary 
to  call  to  mind  some  of  the  chief  epochs  in  the  history  of 
Geology,  and  their  representatives.  This  will  naturally 
lead  us  to  the  point  whence  the  shaft  of  knowledge  has 
been  sunk. 

After  the  middle  of  the  last  century,  Comparative 
Anatomy,  almost  independently  of  systematic  Zoology, 
took  a  prosperous  course,  and  became  far  richer  in 
ideas  than  this  descriptive  Natural  History.  One  of  its 
maxims,  however,  -.vas  accepted  without  examination — 
the  constancy  and  immutability  of  species  ;  and  this 
maxim  forms  the  centre  of  the  views  entertained  by 
Linnaeus.  The  continued  authority  of  this  great  de- 
7 


84  THE  DOCTRINE   OF   DESCENT. 

scriber  of  Nature,  is  rendered  comprehensible  only  by 
the  confident  style  as  well  as  by  the  neatness  of  his 
diagnoses,  by  which,  with  a  single  stroke,  he  put  an  end  to 
the  indefinite  character  of  Natural  History,  and  appeared 
to  contemporaries  and  posterity  as  a  lawgiver.  The 
exaltation  of  species  as  the  basis  of  all  systematic  com- 
prehension had  never  been  so  explicitly  proclaimed. 
His  opinions  culminate  in  the  maxim,'*  "  Reason  teaches 
that  at  the  beginning  of  things,  a  pair  of  each  particular 
species  was  created."  But  with  Linnreus  this  said  reason 
looks  rather  strange,  for  it  is  subservient  to  the  strictest 
Scriptural  belief,  and  he  endeavours  to  harmonize  his 
geological  conceptions  with  this  standpoint. 

One  very  effective  geological  phenomenon  was  espe- 
cially striking  to  him,  namely,  the  upheaval  of  a  great 
portion  of  the  Scandinavian  coast.  It  proceeds  more 
rapidly  than  the  subsidence  of  another  part ;  its  phe- 
nomena are  far  mightier  ;  and  thus  the  idea  might  be 
formed  that  the  continent  had  risen  from  the  sea  in 
regular  progression.  "  I  believe  that  I  am  not  straying 
far  from  the  truth,"  he  says,  "  if  I  affirm  that  in  the 
infancy  of  the  world  all  the  mainland  was  submerged 
and  covered  by  an  enormous  ocean,  save  one  single 
island  in  this  immeasurable  sea,  on  which  all  animals 
dwelt  and  plants  grew  luxuriantly."'* 

It  follows  that  all  species  of  plants  likewise  existed  in 
this  lovely  garden,  as  it  is  expressly  said  that  Adam 
named  every  animal  ;  consequently  all  insects  must 
have  been  assembled  in  Paradise,  but  insects  cannot  be 
imagined  without  plants.  Linnaeus  then  makes  the  first 
attempt  at  animal  geography  by  making  the  animals 
disperse  themselves  from  this  centre.     But  the  summary 


CUVIER.  85 

of  his  idea  of  species  is  invariably,  "We  reckon  as  many 
species  as  the  Infinite  Being  created  at  the  beginning."'" 
And  his  authority  was  so  powerful  that  the  age  of 
Voltaire  and  of  Diderot  devoutly  accepted  this  obvious 
dogma,  and  transmitted  it  to  posterity  as  a  maxim 
impossible  to  question. 

Linnaeus  was,  however,  so  little  of  an  anatomist  that 
in  this  province  Zoology  required  a  completely  fresh 
foundation,  and,  in  the  capacity  of  a  second  Linnaeus, 
Cuvier  stood  forth. '^  His  school  styles  itself  the  school 
of  facts,  yet  it  was  by  no  means  without  a  tincture  of 
philosophy.  On  the  contrary,  the  definite  and  simple 
nature  of  his  principles  and  deductions  could  not  fail  to 
be  imposing.  He  epitomized  the  summary  of  his  obser- 
vations as  "Laws  of  Organization;"  and  he  applied  the 
teleological  view,  the  principe  des  causes  finales,  with 
great  advantage  to  the  knowledge  and  restoration  of 
antediluvian  animals.  The  question  of  the  persistency 
or  mutability  of  species  thrust  itself  forcibly  upon  him. 
For  this  an  external  cause  was  given  by  the  Egyptian 
expedition  and  the  investigation  of  mummified  animals. 
Etienne  GeofTroy  St.  Hilaire  and  Lamarck  attacked  the 
persistency  of  species,  and  held  that,  especially  consider- 
ing the  stability  of  external  conditions,  the  Egyptian 
period  was  far  too  short  for  the  identity  of  the  mummies 
with  the  species  now  extant,  to  make  it  possible  to  infer 
the  immutability  of  species;  but  the  question  was  curtly 
despatched  and  silenced  by  the  predominating  school 
of  Cuvier. 

Meanwhile,  Cuvier  not  only  increased  the  accumu- 
lation of  facts,  but,  as  we  have  already  hinted,  he 
grouped  them  so  happily  and  with  such  philosophical 


S6  THE  DOCTRINE   OF   DESCENT. 

skill  that  he  undoubtedly  approached  the  object  at  which 
he  aimed — the  Natural  System.  He  supplied  the  first 
reliable  information  respecting  extinct  species.  With 
regard  to  those  which  had  replaced  them  in  subsequent 
periods,  he  was  not,  as  is  generally  supposed,  an  un- 
qualified partizan  of  new  creations,  but  he  refrained 
from  any  fixed  opinion.  "  I  v/ill  not,"  he  says,"* 
"positively  affirm  that  for  the  production  of  tlie  present 
animals  a  new  creation  was  required.  I  merely  say 
they  did  not  live  in  the  same  locality,  and  must  have 
come  from  elsewhere."  Gcoffroy  Saint  Hilaire,  on  the 
contrary,  does  not  doubt  that  the  animals  now  living  are 
descended,  by  an  unbroken  succession  of  generations, 
from  the  extinct  races  of  the  antediluvian  age. 

Cuvier's  method  involved  the  danger  of  introducing 
dogmatism  into  natural  science,  and  it  is  therefore 
justifiable  to  refer  in  this  place  to  one  of  Cuvier's  imme- 
diate disciples  only  recently  deceased — Louis  Agassiz, 
who  in  the  most  rigidly  didactic  manner  adheres  to  the 
systematic  categories,  and  invests  them  with  fine-sound- 
ing definitions  as  "  embodied  creative  ideas."  '^  Accord- 
ing to  him,  species  belong  to  a  particular  period  in  the 
world's  history,  and  bear  definite  relations  to  the  physical 
conditions  predominant  at  the  time,  as  well  as  to  the 
contemporaneous  plants  and  animals.  Species  are 
founded  on  well-defined  relations  of  individuals  to  one 
another  and  the  world  in  which  they  live,  as  well  as  on 
the  proportions  and  mutual  relations  of  their  parts,  and 
on  their  ornamentation. 

Individuals,  as  representatives  of  species,  bear  the 
closest  relations  to  one  another  ;  they  exhibit  definite 
relations    also    to   the   surrounding   element,  and  their 


AGASSIZ.  8; 

existence  is  limited  within  a  definite  period.  Of  genera 
he  says,  "  Genera  are  groups  of  animals  most  closely 
connected  together,  and  diverging  from  one  another 
neither  in  the  form  nor  in  the  composition  of  their 
structure,  but  simply  in  the  ultimate  structural  pecu- 
liarities of  some  of  their  parts."  "  Individuals,  as  repre- 
sentatives of  genera,  have  a  definite  and  specific  ultimate 
structure,  identical  with  that  of  the  representatives  of 
other  species." 

We  may  pronounce  these  definitions  to  be  mere 
phrases,  and  inquire  with  Haeckel :  "  Of  what  nature 
are  these  'ultimate  structural  peculiarities  of  some  of 
their  parts'  which  are  supposed  alone  to  define  the 
genus  as  such,  and  to  be  exclusively  characteristic  of 
each  genus  ?  We  ask  every  systematizer  whether  he 
may  not  equally  well  apply  this  definition  to  species, 
varieties,  &c.,  and  whether  it  is  not  finally  the  *  ulti- 
mate structural  peculiarities  of  some  of  their  parts ' 
which  produce  the  characteristic  forms  of  the  species, 
the  variety,  &c.  In  vain  do  we  search  in  the  "Essay 
on  Classification  "  for  a  single  example  of  the  manner 
in  which,  for  instance,  the  genera  of  oxen  or  antelopes, 
the  races  of  hyaenas  and  dogs,  or  the  two  great  genera 
of  our  fresh-water  bivalve  shells,  the  Unio  and  Ano- 
donta,  are  actually  distinguished  by  "  the  ultimate  struc- 
tural peculiarities  of  some  of  their  parts."  Several  of 
these  definitions  given  by  Agassiz  may  be  interchanged 
point-blank,  so  general  and  merely  negative  are  their 
statements.  He  characterizes  the  classes  "  by  the  man- 
ner in  which  the  plan  of  the  type  is  executed  as  far  as 
ways  and  means  are  concerned."  The  orders,  "  by  the 
degree  of  complication  of  the  structure  of  the  types." 


83  THE  DOCTRINE  OF  DESCENT. 

These  phrases  are  interchangeable,  but,  Hke  all  dogma- 
tisnii  they  make  a  great  impression  on  those  who  from 
ignorance  of  the  facts  are  incapable  of  criticising  for 
themselves,  and  they  are  readily  quoted  to  confute  an 
unbelieving  investigation  of  nature  by  one  made  in 
faith. 

It  might  be  thought  that  if  the  affair  were  so  simple, 
and  systematic  ideas  so  firmly  fixed,  nothing  would  be 
easier  than  to  establish  the  system.  And  so  Agassiz 
maintains.  He  says  that  if  a  single  species  of  any  of 
the  great  animal  groups  were  present,  and  admitted  of 
investigation,  the  character  of  the  type,  class,  family, 
genus,  and  species,  might  be  determined.  The  weak- 
ness of  this  and  similar  statements  may  best  be  demon- 
strated by  examining  the  basis  of  all  dogmatic  system, 
— the  "  species."  If  this  idea  be  mutable,  if  the  species 
be  not  given  once  for  all,  but  variable,  according  to 
time  and  circumstances,  the  implications  of  the  higher 
and  more  general  ideas  of  genus,  family,  &c.,  must 
necessarily  ensue.  The  keenest  and  most  logical  criti- 
cism on  the  deeply-rooted  scholastic  idea  of  "  species " 
was  made  by  Haeckel,'"^'^  after  Darwin,  in  his  classical 
work  on  the  "  Origin  of  Species,"  had  completely  ex- 
posed the  old  doctrine  and  practice  of  zoology  and 
botany.     In  what  follows  we  shall  adhere  to  Haeckel. 

We  have  seen  above  that  Linnaeus  accepted  the  Crea- 
tion as  an  irrevocable  scriptural  doctrine,  and  it  is  really 
absurd  that  many  naturalists  who  have  long  abandoned 
any  other  dogma,  should  abide  by  this  one.  Therefore 
as  the  Bible  mentions  the  creation  of  species,  this  legend 
was  made  the  basis  of  all  science.  It  is  true  there  are 
not   now   many   who    appeal   to   scriptural    testimony, 


LINN-'EAN  DEFINITION   OF   SPECIES.  89 

Those  who  defend  the  stabiHty  of  species  rather  imagine 
that,  with  Cuvier,  they  are  entitled  to  interpret  facts  in 
their  own  favour;  whereas  they  partly  remain  uncon- 
sciously involved  in  hereditary  prejudice,  and  partly 
contrive  to  be  deliberately  blind  to  all  that  evidently 
contradicts  the  immutability  of  species. 

Since  Linnaeus  referred  to  the  Creation,  he  attributed 
the  individuals  to  a  species,  of  which  the  pedigree 
ascended  in  direct  line  to  the  pair  which  proceeded 
from  the  hand  of  the  Creator.  Owing  to  the  state  of 
science  in  general,  an  examination  of  this  pedigree  w^as 
totally  impossible  in  his  time ;  and,  indeed,  with  the 
strict  reliance  on  sacred  tradition,  it  was  scarcely  neces- 
sary. Cuvier,  although  a  very  unprejudiced  and  cool 
observer,  nevertheless  radically  accepted  the  Linnaean 
definition  of  species.  According  to  him,  the  species 
is  the  aggregate  of  individuals  descending  from  one 
another  and  from  common  ancestors,  and  of  those 
who  resemble  them  as  strongly  as  they  resemble  one 
another.*' 

"In  this  definition,"  says  Haeckel,  "to  which  the 
majority  have  ever  since  more  or  less  closely  adhered, 
two  things  are  obviously  required  of  an  individual  as 
belonging  to  a  species :  in  the  first  place,  a  certain 
degree  of  resemblance  or  approximate  similarity  of 
character ;  and  secondly,  a  kindred  connection  by  the 
bond  of  a  common  descent.  In  the  numerous  attempts 
of  later  authors  to  complete  the  definition,  the  chief 
stress  is  laid  sometimes  on  the  genealogical  consangui- 
nily  of  all  the  individuals,  sometimes  on  morphological 
uniformity  in  all  essential  characters.  But  it  may  be 
generally  asserted  that  in  the  practical  application  of 


90  THE  DOCTRINE  OF   DESCENT. 

the  idea  of  species,  in  the  discrimination  and  nomencla- 
ture of  the  individual  species,  the  latter  criterion  alone 
has  almost  always  been  employed,  while  the  former  has 
been  entirely  neglected.  Later,  it  is  true,  the  genea- 
logical idea  of  the  common  descent  of  all  individuals  of 
each  separate  species  was  supplemented  by  the 'physio- 
logical definition  that  all  the  individuals  of  every  species 
are  capable  of  producing  fertile  offspring,  by  intercross- 
ing, whereas  sexual  intercourse  between  individuals  of 
different  species  produces  only  sterile  offspring  or  none  at 
aU.  In  practice,  however,  it  was  considered  quite  enough 
if,  among  a  number  of  extremely  similar  animals  under 
investigation,  uniformity  in  all  essential  characters  could 
be  established,  and  no  inquiry  was  made  whether  these 
individuals  ascribed  to  the  same  species  were  actually 
of  common  origin,  and  capable,  by  crossing,  of  pro- 
ducing fertile  offspring.  The  physiological  definition 
was  no  more  applied  in  the  practical  discrimination  of 
animal  and  vegetal  species,  than  was  the  pre-supposed 
common  descent  from  a  single  ancestral  pair.  OA  the 
other  hand,  two  closely  allied  forms  were  distinguished 
without  scruple  as  two  different  'good  species,'  when- 
ever in  a  number  of  similar  individuals  examined  a  con- 
stant difference  could  be  demonstrated,  even  though  of 
a  merely  subordinate  character.  Here,  again,  no  pains 
were  taken  to  ascertain  whether  the  two  different  series 
were  not  really  descended  from  common  ancestors,  and 
wer^  really  capable  of  generating  in  conjunction  only 
sterile  hybrids,  if  any." 

That  this  radical  condemnation  of  the  post-Linnaean 
manufacture  of  species  is  not  too  severe,  is  shown  by 
one  fact  among  others  ;  that  within  the  fraternity  such 


NO  ESSENTIAL  CHARACTERISTICS  OF  SPECIES.     9I 

Utter  discord  as  to  the  limitations  of  species  prevailed, 
and  still  prevails,  that  no  agreement  can  be  arrived  at 
respecting  the  basis  of  the  description  of  species,  the 
"essential  characteristics."  Although  Agassiz  lays  down 
the  diagnosis  of  the  species,  a  decision  is  required  in  each 
case  as  to  the  mutual  relations  of  the  parts,  the  orna- 
mentation, &c.  As  in  the  absence  of  birds'-nests,  snail- 
shells,  butterflies,  &c.,  it  is  impossible,  when  it  comes  to 
the  erection  of  species,  to  pre-determine  what  may  be 
the  "  essential  characteristics  "  of  the  species  they  are  to 
form,  subjective  opinions  and  arbitrary  decisions  have 
full  play;  and  v/ithin  a  certain  domain,  well  known  by  its 
forms,  there  are  among  the  systematizers  no  two  autho- 
rities who  are  agreed  as  to  the  number  of  species  into 
which  the  material  before  them  should  be  divided. 

The  most  unbridled  license  in  tlie  manufacture  of 
species  prevailed,  however,  among  the  Palaeontologists 
during  a  period  when,  in  the  endeavour  to  fix  the  sub- 
divisions of  geological  strata  as  accurately  as  possible  by 
means  of  their  organic  contents,  the  separation  of  species 
was  carried  incredibly  far,  into  the  most  minute  and  often 
into  individual  deviations.  A  certain  mutability  of  species 
could  not  fail  to  obtrude  itself  on  the  most  purblind  eye  ; 
ramifications  were  made  of  sub-species,  sports  of  nature, 
and  varieties  characterized  by  "  less  essential "  peculiari- 
ties acquired  by  means  of  climate  and  inheritance. 
There  was,  however,  always  a  reservation  that  their 
crosses  with  one  another  and  with  the  main  species 
should  produce  fertile  oftspring,  whereas  towards  other 
species  their  relations  were  identical  with  those  of  the 
main  species.  Of  course,  in  this  separation  of  the 
species  into  sub-species,  subjective   opinion   was   even 


92  THE   DOCTRINE  OF  DESCENT. 

less  fettered  by  tradition  and  law  than  in  the  definition 
of  =pecies.  The  literature  of  ornithology  during  the  last 
forty  years  could  furnish  thousands  of  the  strangest 
examples  of  the  Babel-like  confusion  which  was  thus 
introduced. 

There  is  no  question  that  a  great,  perhaps  the  greater, 
number  of  organisms  now  existing  are  in  a  condition 
in  which,  according  to  their  internal  and  external  re- 
lations, they  may  be  characterized  by  Natural  History 
as  so-called  species,  and  for  the  purpose  of  recognition 
ard  scientific  treatment  in  general,  must  needs  be  so 
characterized.  But  this  stability,  as  may  be  shown  both 
directly  and  by  analogy,  is  under  all  circumstances  only 
temporary,  and  we  have  whole  classes  of  organisms  to 
which  it  is  impossible,  even  with  the  widest  reservations, 
to  apply  the  old  idea  of  species,  with  its  immutability  of 
essential  characteristics.  If  we  a|-e  able  to  furnish  incon- 
trovertible proofs  of  the  existence  of  such  non-specific 
groups,  the  old  system  and  the  dogma  of  species  are  once 
for  all  set  aside,  and  the  positive  basis  of  a  new  doctrine 
is  secured.  This  evidence  is  supplied  in  two  directions. 
Some  classes  of  organisms  in  their  present  state  vacillate 
and  fluctuate  in  form,  in  such  a  manner  that  it  is  utterly 
impossible  to  fix  the  characteristics  of  species  or  genus. 
They  are  in  an  extreme  grade  of  mutability,  which,  in 
others,  has  given  way  to  an  apparent  state  of  repose. 
Other  series  of  facts,  exhibiting  the  most  obvious  muta- 
bility of  species,  are  displayed  by  certain  antediluvian 
groups  in  the  succession  of  forms  called  "  species." 

Even  before  the  appearance  of  Darwin's  work  on  the 
"Origin  of  Species,"  Carpenter,- in  the  course  of  his 
researches    on    the    Foraminifera,    arrived  at  the  cou' 


SERIES   OF    rCRMS   IN   SPONGES.  93 

elusion,  proved  in  special  instances,  that  in  this  group 
of  low  organisms  which  secrete  the  most  delicate  cal- 
careous shells,  there  could  be  no  question  of  "  species," 
but  only  of  "  series  of  forms."  Forms  which  the  sys- 
tematists  had  reduced  to  different  genera  and  families, 
he  beheld  developing  themselves  from  one  another. 
These  Foraminifera  are,  however,  so  simple  in  structure, 
the  history  of  their  individual  evolution  or  Ontogenesis 
is,  as  yet,  so  little  known ;  they  contribute  so  little 
microscopic  detail,  which  might  formulate  the  law  of 
transmutation  of  species,  that  the  champions  of  persist- 
ency of  species  might  still  seek  refuge  in  the  assertion 
that  Carpenter's  series  of  forms  are  mere  varieties,  and 
only  prove  that  the  true  "  species  "  have  not  yet  been 
found. 

We  may  now  turn  with  advantage  to  the  class  of  the 
Spongiadae,  the  importance  of  which  in  the  question  of 
species  I  was  the  first  to  point  out.^*  With  them,  as  I 
summed  up  my  researches,  it  is  not  as  with  the  Forami- 
nifera, merely  an  affair  of  the  general  habit  of  the  form, 
of  the  variable  grouping  of  the  chamber  systems;  but  the 
variability  exists  still  more  specially  in  the  microscopic 
detail  than  in  the  coarser  constituents.  In  the  Forami- 
nifera we  may  speak  of  microscopic  forms,  but  not  pro- 
perly of  microscopic  constituents.  But  in  the  sponges 
we  discern  the  transformation  of  the  finer  morphological 
constituents,  the  rudimentary  organs,  and  we  thereby 
gain  an  insight  into  the  mutability  of  the  whole.  In  this 
respect  the  calcareous  sponges  are  somewhat  differently 
circumstanced  from  the  rest,  and  from  the  silicious 
sponges  in  particular.  In  the  former,  the  variability  of  the 
microscopic  parts  is  limited  to  a  smaller  circle  of  forms, 


94  THE   DOCTRINE   OF  DESCENT. 

whereas  the  habit  of  the  series  of  individuals  is  incredi- 
bly variable.  This  variability  of  the  whole  body  is  not 
lacking  in  the  silicious  sponges  ;  in  the  genus  Tedania, 
for  instance,  established  by  Gray  from  some  of  my  earlier 
Reniera,  we  see  how  their  stubbornly  coherent  needle-like 
forms  recur  from  Trieste  to  Florida  and  Iceland,  under 
the  most  heterogeneous  disguises.  In  some  varieties,  how- 
ever, one  of  these  spicula  already  manifests  a  tendency  to 
deviations. 

This  very  point,  the  possibility  of  tracing  in  detail 
the  metamorphoses  of  organs,  which,  on  the  assumption 
of  their  stability,  appeared  to  provide  the  system  with 
the  most  substantial  basis  for  the  erection  of  genera  and 
species,  renders  the  investigation  peculiarly  attractive. 
Even  among  the  Algierian  sponges,  I  have  adduced 
striking  examples,  and  they  accumulate  in  proportion 
as  the  horizon  is  extended.  We  arrive  gradually  at  the 
conviction  that  no  reasonable  dependence  can  be  placed 
on  any  "characteristic;"  that  with  a  certain  constancy 
in  microscopic  constituents,  the  outward  bodily  form, 
with  its  coarser  distinctive  marks,  varies  far  beyond  the 
limits  of  the  so-called  species  and  genera  ;  and  that, 
with  like  external  habits,  the  internal  particles,  which 
we  looked  upon  as  specific,  are  transformed  into  others, 
as  it  were,  under  our  hands.  "Any  one" — thus  con- 
cludes this  section  of  my  work  on  the  Fauna  of  the 
Atlantic  Sponges, — "  who,  with  regard  to  sponges, 
makes  his  chief  business  the  manufacture  of  species  and 
genera,  is  reduced  ad  absiirdiini,  as  Haeckel  has  show^ 
with  exquisite  irony  in  his  Prodrome  to  the  Monograph 
on  the  Calcareous  Sponges." 

In  my  specific  researches  I  confined  myself  essentially 


NO  ABSOLUTE  SPECIES  EXISTS.  95 

to  the  silicious  sponges,  and  by  thousands  of  microscopic 
observations,  by  measurements,  by  drawings,  by  facts 
and  inferences,  had  produced  evidence,  which  acute  op- 
ponents of  the  immutabihty  of  species  had  not  brought 
forward  before  me,  that  in  these  sponges,  species  and 
genera,  and  consequently  fixed  systematic  unities  in 
general,  had  no  existence.  The  other  division  of  the 
same  class,  the  calcareous  sponges,  had  been  treated 
with  unrivalled  mastery  by  Haeckel  in  his  Monograph.^' 

He  was  able  not  only  to  confirm  my  statements,  but, 
owing  to  the  smaller  compass  and  the  greater  facility 
of  observing  the  group  selected  for  study,  to  advance 
with  more  sequence  and  continuity  from  the  observation 
of  details  to  the  whole,  to  portray  its  morphology, 
physiology,  and  evolutionary  history  with  the  utmost 
completeness.  He  then  challenged  the  obstructive 
party  with  the  assertion  that,  according  to  subjective 
opinion,  either  one  or  591  species  of  calcareous  sponges 
might  be  accepted,  but  "  that  no  absolute  species  exists, 
and  that  species  and  varieties  cannot  be  sharply  sepa- 
rated." Whoever  after  these  demonstrations  cleaves  to 
the  phantom  of  species,  without  either  proving  that 
the  facts  have  been  falsely  observed,  or  that  they 
may  be  interpreted  otherwise  than  in  favour  of  the 
stability  of  species, — whoever,  as  Agassiz  has  recently 
done,  ignoring  any  such  researches,  publicly  asseverates 
that  in  no  single  case  has  the  mutability  of  any  species 
been  exhibited, — scarcely  preserves  the  right  to  partici- 
pate in  the  great  controversy  by  which  Natural  Science 
is  now  perturbed. 

There  is,  however,  as  we  have  already  mentioned,  a 
second  direction  in  which  the  mobility  of  "  species  "  must 


96  THE   DOCTRINE   OF   DESCENT. 

be  demonstrated,  not  the  direction  of  breadth,  but  of 
heio-ht  and  depth.  This  mutability  of  the  SpongiadcC 
affords  the  extremely  important  evidence  that,  so  to 
speak,  an  entire  class  has,  even  now,  not  attained  a 
state  of  comparative  repose.  But  to  confirm  the  mu- 
tability of  species,  evidence  of  mutability  in  lapse  of 
time  is  justly  demanded;  the  transition  of  the  forms 
succeeding  one  another  historically  in  the  strata  of  the 
earth. 

In  former  editions  I  expressed  a  belief  that  a  highly 
instructive  instance  of  the  modification  of  a  species  in 
time  might  be  seen  in  the  Planorbis  from  the  fresh- 
water deposits  of  Steinheim,  described  by  Hilgendorf. 
But  this  very  example  has  served  to  warn  us  how 
cautious  we  must  be  in  accepting  proofs,  since  later 
observers  have  sought  in  vain  for  the  regular  succession 
of  strata  that  was  said  to  exist,  and  the  series  of  modi- 
fied forms  of  Planorbis  multiformis  contained  in  them; 
indeed,  they  convinced  themselves  on  the  contrary,  that 
the  unusually  divergent  forms  of  this  snail  occur  mingled 
throughout.  However,  other  evidences  of  such  modifica- 
tion abound,  and  the  zeal  of  some  recent  Palaeontologists 
— Waagen,  Zittel,  Kayser,  Neumayr,  and  Wurtenberger — 
has  proved,  by  following  up  the  species,  so  called,  of 
Brachiopoda  and  Ammonitidse  through  vast  geological 
periods,  that  it  is  impossible  to  arrange  these  large  groups 
under  true  species.  I  will  allow  these  naturalists  to  speak 
for  themselves. 

Kayser  concludes  from  an  investigation  of  the 
Brachiopoda  of  the  Devonian  beds  of  the  Eifel : — "  No 
order  of  animals,  perhaps,  yields  such  strong  evidence 
in  favour  of  the   Darwinian  theory  as  the  Brachiopoda. 


METAMORPHOSIS   OF  AMMONITES.  97 

Any  one  who,  like  myself,  has  had  occasion  to  trace  a 
great  number  of  these  fossils  through  several  strata  of 
considerable  extent  and  thickness,  and  to  handle  hun- 
dreds cf  every  species  as  heretofore  classified,  must 
often  have  been  astonished,  to  see  how  wide  is  the 
divergence  in  many  of  these  species.  Often  he  must 
have  lost  all  hope  of  ever  arriving  at  a  clear  delimita- 
tion of  species;  again  and  again  must  he  have  felt  less 
inclined  to  dismiss  the  idea  put  forward  by  Darwin, 
'  that  our  species  are  in  fact  only  an  artificial  concept,  a 
mere  formula.'  Kayser  consequently  finds  himself  com- 
pelled to  adopt  purely  artificial  limits,  and  speak  of 
'  Form-series,'  as  other  writers  do  of  Ammonites.  Waagen 
reminds  us  that,  long  before  Darwin,  Queenstedt  had 
suggested  the  Genetic  connection  of  successive  forms  in 
geological  strata,  and  he  then  says : — "  There  are  but 
few  among  the  Palaeontologists  who  have  recently 
studied  the  Ammonitidse  under  the  light  of  the  Theory 
of  Descent,  to  whom  the  facts  have  not  brought  convic- 
tion. The  existence  of  Form-series,  such  as  have  been 
shown  again  and  again  by  late  investigators — series  in 
which  each  more  recent  form  deviates  but  slightly  from 
its  precursor,  till  the  sum  total  of  these  small  divergences 
results  in  a  wide  dissimilarity  from  the  original  species — 
points  with  coercive  clearness  to  the  assumption  of  Genetic 
connection." 

Zittel  and  Neumayr  are  of  the  same  mind.  Neumayr 
writes  : — "  There  is  hardly  any  fact  which  speaks  so 
conclusively  for  the  validity  of  the  Theory  of  Descent  as 
the  existence  of  Form-series,  which  has  been  proved  in 
many  cases,  and  of  which  more  instances  will  certainly 
be  found  now  that  attention  has  been  directed  to  the 
matter.     A  peculiarly  beautiful  example  is  to  be  seen — 


98  THE   DOCTRINE   OF   DESCENT. 

the  form  here  described  of  Oppelia  Darwinii,  as  a  tran- 
sition form  between  the  normal  type  of  Pennilobata  and 
the  abnormal  semi-forms."  Neumayr  confirms  many  of 
Wurtenberger's  most  important  discoveries,  which  I  will 
proceed  to  quote. 

L.  Wiirtenberger  applied  his  researches  to  thousands 
of  samples  from  the  groups  of  the  Planulate  Ammonites 
with  ribbed  shells,  and  of  the  Armate  Ammonites  with 
prickly  shells.  In  summing  up  his  results  he  says, 
among  other  things  :  "  How  among  the  Ammonites  of 
the  Planulate  and  Armate  groups,  the  species  are  to  be 
branched  off  from  one  another,  I  should  be  reluctant  and 
unable  to  give  any  instructions,  for  to  me  this  question 
appears  utterly  hopeless.  For  in  groups  of  fossil  organ- 
isms, in  which,  as  in  the  present  case,  so  many  connect- 
ing links  between  the  most  extreme  forms  are  actually 
before  us,  that  the  transition  is  regularly  carried  on,  the 
species  is  far  less  susceptible  of  apprehension  than  in  the 
organic  forms  of  the  present  world,  which  at  least  denote 
the  existing  limits  of  the  great  pedigree  of  the  organic 
world.  With  respect  to  these  fossil  forms,  it  is  funda- 
mentally indifferent  whether  a  very  short,  or  a  somewhat 
longer  portion  of  any  branch  be  honoured  bya  special 
name,  and  looked  upon  as  a  species.  The  prickly  Am- 
monites, classified  under  the  name  of  Armata,  are  so 
intrinsically  connected,  that  it  becomes  an  impossibility 
to  separate  the  accepted  species  sharply  from  one 
another.  The  same  observation  applies  also  to  the 
group  of  which  the  manifold  forms  are  distinguished 
by  their  ribbed  shells,  and  termed  Planulata."  It  has 
further  transpired  that  the  Armata,  or  Custata,  originated 
from  the  Planulata. 


SPECIES  AND   HYBRIDS.  99 

Wc  shall  return  later  to  Wurtenberger's  preliminary 
communications.  It  was  our  object  here  to  inform  our 
readers  how  and  where  modern  natural  inquiry  sets  aside 
the  phantom  of  species,  and  to  enable  them  to  judge  for 
themselves  what  series  of  observations  are  opposed  to 
the  asseverations  that  in  no  single  case  has  evidence 
been  given  of  the  transition  of  one  species  into  another. 
For  the  old  school  falls  into  the  dilemma  of  proclaiming 
whole  orders  and  classes  to  be  **  species,"  and  the  species, 
formerly  so  beautifully  defined,  to  be  varieties. 

The  untenableness  of  the  physiological  part  of  the 
definition  of  species  has  been  conclusively  shown  first  by 
Darwin  and  afterwards  by  Haeckel.  It  is  known  that 
even  in  a  state  of  freedom  good  species  not  infrequently 
breed  together,  and  that  domesticated  species,  such  as 
the  horse  and  the  ass,  have  been  crossed  for  thousands 
of  years.  But  hybrids,  the  produce  of  this  intercourse, 
were  supposed  to  be  only  exceptionally  fertile,  and  at 
any  rate  not  to  produce  fertile  progeny  for  more  than  a 
few  generations.  On  the  other  hand,  it  was  considered 
certain  that  the  produce  of  crosses  among  varieties  are 
fertile  in  unbroken  succession.  The  dogma  of  the  ste- 
rility of  hybrids  was  formed  without  any  experimental 
or  general  observ'ation,  and  by  ill-luck  was  apparently 
confirmed  by  the  most  ancient  and  best  known  hybridi- 
zations of  the  mule  and  the  hinny.  To  this  familiar 
example,  in  which  the  fertility  of  hybrids  proves  abortive, 
we  will  oppose  only  one  case  of  propagation  successfully 
accomplished  in  recent  times  through  many  generations; 
that,  namely,  of  hares  and  rabbits,  two  "  good  species  " 
never  yet  regarded  as  mere  varieties. 

The  numerous  and  varied  forms  of  the  domestic  do^f 

6 


too  THE   DOCTRINE   OF   DESCENT. 

were  pronounced  ex  cathedrd  to  be  varieties  of  the  same 
species,  as  tiieir  crosses  are  productive.  But  after  read- 
ing Darwin's  careful  comparison  of  the  reports  as  to 
the  relations  of  certain  species  of  wolves  with  the  dogs 
of  savage  nations,  and  of  the  European  wolf  with  the 
Hungarian  dog,  we  must  agree  with  Darwin  in  thinking 
it  as  extiemely  probable  that  in  various  parts  of  the 
world,  and  at  various  periods,  wild  species  of  the  genus 
Canis  were  domesticated,  of  which  the  crosses  produce 
fertile  progeny  to  an  extent  almost  unlimited. 

It  is  the  same  with  the  domestic  cat.  With  the  forms 
of  the  European  domestic  cat,  the  case  is  such  that  it 
is  scarcely  possible  to  doubt  its  origin  partly  from  a 
Nubian  species,  and  partly  from  the  European  wild- 
cat. The  inferences  thus  moved  in  a  circle  ;  forms  be- 
long to  the  same  species,  because  they  may  be  fruitfully 
crossed  ;  and  because  they  may  be  fruitfully  crossed, 
they  belong  to  the  same  species;  and,  on  the  other  hand, 
because  such  and  such  forms,  when  crossed,  produce  no 
fertile  progeny,  they  constitute  different  species  ;  and 
because  they  are  different  species,  they  generate  no  fertile 
offspring.  The  cases  of  persistent  fertility  in  hybrids  are 
certainly  not  frequent,  but  they  are  nevertheless  so  well 
certified  that  the  contrary  statement  is  in  plain  contra- 
diction to  the  facts.  But  conversely,  the  proposition 
that  mongrels,  the  products  of  crosses  among  varieties, 
are  fertile,  thus  generally  stated,  is  likewise  untenable. 
The  variety  which  has  been  evolved  in  Paraguay  front 
our  domestic  cat,  pairs  no  longer  with  its  ancestral  stock, 
nor  does  the  tame  European  guinea-pig  with  the  wild 
ancestral  stock  of  Brazil. 

But  even  if.  in  general,  crosses  between  varieties  are 


GEORGE  FORSTER.  lOI 

more  easily  effected,  and  more  often  produce  fertile  off- 
spring than  the  unquestionably  rarer  crosses  of  species 
the  frequent  failure  of  crosses  between  species  com- 
pletely accords  with  the  modification  of  species  in  the 
lapse  of  time,  as  shown  above.  Provisionally,  let  us 
hold  nothing  to  be  established  but  that,  as  to  fertility 
and  the  capability  of  persistent  reproduction,  the 
conditions  of  mongrels  and  of  hybrids  are  essentially 
similar  and  differ  only  in  degree,  and  that  on  these 
properties,  no  closer  definition  or  limitation  can  be 
founded. 

If  the  older  definitions  of  species  go  back  to  Paradise, 
and  derive  existent  species  lineally  from  ancestral  pro- 
genitors, miraculously  created  from  the  first  and  never 
modified,  the  ingenuous  statements  of  Linnaeus  show  that 
all  this  was  accepted  as  self-evident,  and  that  no  thought 
was  given  to  the  proof,  which  would  indeed  have  been 
impossible  to  obtain.  A  letter  from  George  Forster  to 
Peter  Camper,  dated  May  7th,  1787,  proves  howevei 
that,  even  in  the  last  century,  the  voices  of  more  far- 
sighted  naturalists  were  raised  against  this  superficial 
treatment  of  the  idea  of  species.  Systems,  he  said,  were 
founded  on  this  idea,  yet  everything  was  uncertain  as 
long  as  this  expression  was  not  irremovably  fixed.  But 
hitherto  all  definitions  of  this  word  were  hypothetical, 
and  in  themselves  anything  but  clear.  If  we  are  to 
accept  as  many  species  as  were  created,  how  is  a 
created  species  to  be  distinguished  from  one  produced 
by  the  intermixture  of  several  others  }  To  fall  back 
upon  the  Creation  is  to  lose  oneself  in  the  Infinite 
and  the  Impalpable.  "  This  will  never  enable  us  to 
understand  anything  ;  and  definitions  which  rest  on  an 


102  THE   DOCTRINE   OF   DESCENT. 

inexplicable  foundation,  on  a  mystery,  ought  to  be  pro- 
scribed from  science  for  evermore." 

Without  owning  allegiance  to  any  theory  whatever, 
we  are  constrained  to  recognize  the  fact,  that  in  various 
groups  of  organisms  there  even  now  exists  such  an 
instability  of  form,  and  such  a  degree  of  variability, 
that  it  is  patent  how  constrained  and  artificial  is  their 
systematic  separation.  In  many  other  groups,  in  most 
orders  of  the  Mammalia,  for  example,  this  phase  of 
mobility  has  been  replaced  by  a  certain  quiescence,  and 
the  forms  now  presenting  themselves  for  observation 
and  comparison  are  so  well  defined  from  one  another, 
that  they  fit  into  the  system  without  difificiilty  as  "  good 
species."  But  if  the  "good  species"  are  to  be  judged 
by  the  experiences  made  in  regard  to  the  "bad"  ones, 
and  if  the  preposterous  hypothesis  is  not  laid  hold  of,  in 
contravention  to  all  healthy  human  understanding,  that 
"  good  species  "  originated  in  a  miraculous  manner  inac- 
cessible to  our  cognition,  whereas  the  "  bad  species  "  are 
susceptible  of  analysis, — the  other  alternative  alone  is 
possible,  that,  as  Haeckel  says,  if  we  knew  them  tho- 
roughly, all  species  without  exception  would,  in  the  sense 
of  the  species-makers,  be  "bad  species."  We  are  also 
acquainted  with  a  sufficient  number  of  bad  species  to  be 
capable  of  inferring  the  general  law  with  certainty. 
Nevertheless,  all  further  corroboration  and  discovery  of 
bad  species  is  acceptable.  Regarded  formerly  by  the 
systematists  only  as  incumbrances  and  as  stones  rejected 
by  the  builders,  they  have  now  become  the  corner-stones 
of  science. 

Is  species  therefore,  we  again  inquire,  to  be  entirely 
abandoned  ?    Not  so,  for  several  reasons.    Even  assuming 


SPECIES  ONLY  RELATIVELY   STABLE.  IO3 

that  so-called  good  species,  in  the  sense  of  the  sy^tematists, 
have  no  existence,  human  intellect,  in  the  endeavour  to 
obtain  a  general  view,  would  be  compelled  to  denominate 
the  forms,  unless  all  scientific  treatment  was  to  be  ren- 
dered impracticable.  But  the  retention  of  species  is  more- 
over scientifically  justifiable  and  necessary,  if  only  the 
determining  impulses  be  taken  into  account,  and  the 
definition  reduced  to  harmony  with  reality.  Species 
is  not  constituted  merely  of  analogous  individuals,  for 
even  the  sexes,  in  the  course  of  development,  and  without 
transformation,  diverge  considerably  from  one  another. 

But  if  we  remember  the  transmutation  of  shape  taking 
place  by  stages  in  organisms  subject  to  metamorphosis, 
and  the  regular  sequence  of  forms  alternating  with  one 
another  in  heterogenesis,  we  shall  be  obliged  to  speak, 
not  of  individuals,  but  of  the  cycles  of  reproduction 
which  comprise  the  various  phases  and  series  of  indi- 
viduals. These  remain  persistent  as  long  as  they  exist 
under  the  same  external  conditions.  How  far  time  in 
itself  affects  existence  and  decay  is  unknown.  At  any 
rate,  time,  as  well  as  the  external  conditions  of  time,  is 
a  factor  in  the  mutation  of  species.  While  we  regard 
species  as  absolutely  mutable,  and  only  relatively  stable, 
we  will  term  it,  with  Haeckel,  "the  sum  of  all  cycles  of 
reproduction  which,  under  similar  conditions  of  exist- 
ence, exhibit  similar  forms." 


f04  THE   DOCTRINE  OF   DESCliNT. 


VI. 

Natural    Philosophy— Goethe  — Predestined    Transformation    according    to 
Richard  Owen— Lamarlc.    . 

We  have  hitherto  confined  ourselves  essentially  to  the 
contemplation  of  the  phenomena  of  the  animal  world  as 
facts,  avoiding-  as  far  as  possible  any  examination  of  the 
correlation  of  these  facts,  or  any  criticism  of  the  attempts 
to  explain  them.  It  was  nevertheless  necessary  to  single 
out  from  the  history  of  our  science  some  few  impulses  of 
which  the  after-effects  extend  to  the  present  time,  and 
of  which  a  knowledge  is  conducive  to  the  comprehension 
of  prevailing  views,  tendencies,  and  prejudices.  For  this 
reason  we  again  revert  to  the  evolutionary  history  of 
Biology  and  Comparative  Anatomy,  that  we  may  trace 
the  present  currents  to  their  sources.  Since  the  middle 
of  last  century,  there  has  been  no  lack  of  leading  ideas 
in  the  organic  natural  sciences,  such,  for  instance,  as  are 
contained  in  Buffon's  magnificent  project  of  a  picture  of 
the  world.  But  if  it  is  a  question  of  a  single  compre- 
hensive solution  of  the  organic  world,  we  are  at  once 
reminded  of  the  claims  preferred  by  Natural  Philo- 
sophy in  the  first  decades  of  this  century,  to  explain  the 
universe ;  to  derive  from  the  whole,  not  only  matter 
in  the  abstract,  but  the  being  and  origin  of  organic 
bodies.      When    the    Philosophy  of   Identity  began  to 


OKEN.  105 

found  the  laws  of  the  Mind  without  the  study  of  the 
body,  and  in  its  own  fashion  had  proved  the  identity  of 
the  corporal  and  spiritual  world  by  means  of  imponder- 
ables and  non-organic  bodies,  their  constructions  neces- 
sarily extended  to  organisms. 

This  attempt  to  generalize  the  principles  of  Schelling 
was  made  by  Oken  '^"^  when  in  his  system  he  conceives 
all  Nature  to  be  a  process  of  evolution.  In  his  opinion, 
natural  science  is  the  science  of  the  eternal  modification 
of  God,  that  is  of  ]\Iind,  in  the  world,  and  is  thus  in  the 
widest  sense.  Cosmogony.  Everything,  when  contem- 
plated as  part  of  the  genetic  process  of  the  whole, 
involves,  besides  the  idea  of  existence,  also  that  of 
non-existence,  or  position  and  negation,  as  it  rises  into  a 
higher  idea.  These  contrasts  include  the  category  of 
polarity,  w^hich  manifests  itself  in  motion,  the  life  of  all 
things.  The  simpler  elementary  bodies  aggregate  into 
higher  forms,  which  are  mere  higher  powers  of  the  former, 
as  their  causes.  Hence  the  various  classes  of  bodies 
represent  parallel  series,  each  corresponding  with  and 
modifying  the  order  of  the  other ;  classes  of  which  the 
rational  arrangement  follows  with  inherent  necessity  from 
their  genetic  coherence.  But  in  individuals,  these  lower 
series  again  become  apparent  during  the  period  of  de- 
velopment. The  antagonisms  in  the  solar  system  of 
the  planets  and  the  sun,  repeat  themselves  in  plants 
and  animals  ;  and  as  light  is  the  principle  of  motion,  the 
animal  has  the  advantage  of  independent  motion,  above 
the  vegetal  organism  which  pre-eminently  belongs  to  the 
earth.  Embryology  receives  its  due  in  a  general  propo- 
sition. **  Animals  perfect  themselves  gradually,  adding 
organ  to  organ  in  the  self-same  manner  as  the  individual 


f06  THE   DOCTRINE   OF   DESCENT. 

animal  is  perfected."  But  in  Man,  as  the  highest  animal, 
the  whole  animal  world  is  contained  ;  he  is  the  actual 
Microcosm. 

If  Natural  Philosophy  be  the  expression  and  logical 
connection  of  all  well-observed  facts,  we  could  not  now 
designate  as  Natural  Philosophy,  Oken's  well-rounded 
system,  laid  down  in  3562  propositions,  with  their  in- 
ferential conceits  of  Position,  Negation,  and  Polarity, 
the  absolutely  meaningless  formula  of  +  O  —  without 
any  real  penetration  of  the  subject-matter.  Various 
and  important  incitements  to  research  were  nevertheless 
supplied  by  it,  and  we  have  been  the  more  anxious  to 
call  attention  to  this  system,  as  it  implies  at  least  as 
much  as  the  vague  formulae  and  ideas  of  "  intrinsic  de- 
velopment," the  "  principle  of  progress,"  the  "  conversion 
of  the  lower  into  the  higher,"  and  the  whole  litany  of 
indecision  and  indistinctness. 

In  this  chapter  we  shall  not  adhere  to  chronological 
succession,  but  merely  characterize  various  theories  of 
organic  nature ;  and  we  may  therefore  now  revert  to 
Goethe,  who  in  Haeckel's  opinion  forestalled  his  age  on 
the  great  question  which  forms  the  subject  of  this  book, 
and  deserves  to  be  honoured  as  the  independent  founder 
of  the  theory  of  descent  in  Germany."**  We  cannot 
ascribe  this  importance  to  Goethe,  for  we  must  deny 
the  very  cardinal-point  on  which  Haeckel  lays  most 
weight, — that  Goethe  regards  species  not  merely  as 
modified  phenomena  of  the  variable  idea  of  the  genus, 
but  as  the  sum  of  bodies  modifiable  in  the  concrete. 
What  principally  induces  us  to  make  detailed  mention 
of  Goethe  is  his  penetration  of  the  idea  of  type,  which 
since  the  time  of   Buffon   had  been    for    two   genera- 


GOETHE.  107 

tions  the  lodestar  of  a  higher  research  unlcnown  to  the 
pure  systematizers.  Goethe  elaborated  this  idea  in  his 
own  mind  on  the  basis  of  a  certainly  remarkable  special 
knowledge  of  organic  matter,  and  undeniably  reached 
the  threshold  of  the  solution.  That  his  scientific  activity 
was  a  necessary  effusion  of  his  nature,  I  have  demon- 
strated in  the  treatises  here  cited.  Additional  evidence 
has  been  given  by  Helmholtz  and  Virchow. 

Goethe's  notes  on  his  position  towards  nature,  and  his 
researches,  comprise  a  period  of  more  than  fifty  years. 
About  the  year  1780,  there  appears,  under  the  title  of 
"  Die  Natur,"  a  sort  of  Hymn  to  Nature,  concluding 
with  the  beautiful  words  which  make  him  seem  a  pure 
Pantheist :  "  She  placed  me  in  it ;  she  will  also  lead  me 
forth ;  I  trust  mycelf  to  her.  She  may  dispose  of  me. 
She  will  not  hate  her  work.  I  spake  not  of  her.  No, 
whatever  is  true  and  whatever  is  false,  she  spake  it  all. 
All  is  her  fault,  and  all  is  her  merit."  And  shortly 
before  his  death,  in  March,  1832,  he  threw  his  whole  soul 
into  the  scientific  controversy  as  to  the  difi*erent  methods 
of  the  investigation  of  nature  and  the  fundamental 
principles  of  study,  which  rose  high  in  the  midst  of  the 
French  Academy  between  the  two  renowned  represen- 
tatives of  the  inductive  and  deductive  tendencies,  Cuvier 
and  Geofi'roy  St.  Hilaire.  What  Goethe  here  laid  down 
in  the  evening  of  his  days,  is  a  sort  of  scientific  profes- 
sion of  faith,  and  it  inspires  the  greatest  admiration  to 
behold  the  venerable  octogenarian  standing  on  the  pin- 
nacle of  time,  and  above  all  parties,  with  the  same 
principles  which  with  his  own  powers  he  had  framed 
for  himself  five-and-forty  years  before,  in  the  prime  of 
manhood. 


I08  THE   DOCTRINE  OF   DESCENT. 

In  the  height  of  his  genius,  when  Goethe,  standing  at 
the  centre  of  the  life  of  Weimar,  frequently  withdrew 
from  the  bustle  of  the  town  and  court,  he  received  the 
first  suggestions  of  the  "  Metamorphosis  of  Plants."  He 
was  irresistibly  attracted  to  the  varying  phenomena  of 
vegetal  life,  and  he  could  but  muse  on  the  implied  unity 
and  rule  underlying  this  variation.  This  was  a  fresh 
source  of  agitation,  which  pursued  him  when,  in  1787,  he 
forcibly  tore  himself  from  the  influences  of  Weimar  and 
fled  to  Italy.  There,  in  Sicily,  he  found  the  solution  of 
the  riddle  :  the  leaf  seemed  to  be  the  rudimentary  organ 
of  vegetal  structure.  And  when,  after  his  return,  a  new 
star  rose  for  him  in  Christiana  Vulpius,  he  laid  down 
the  quintessence  of  his  ideas  on  the  Metamorphosis  of 
Plants  in  that  exquisite  poem,  of  which  the  lines — 

*'  All  forms  have  a  resemblance,  none  is  the  same  as  another, 
And  their  chorus  complete  points  to  a  mystical  law, 
Points  to  a  sacred  riddle, — "  * 

are  present  to  all  who  ever  made  themselves  acquainted 
with  the  muse  of  Goethe.  He  now  saw  in  the  various 
parts  of  the  plant  what  he  had  learnt  to  see  with  the 
eye  of  the  imagination,  which  he  considers  essential  to 
the  Naturalist,  —  the  harmonizing  principle.  "  The 
same  organ  may  be  expanded  into  a  compound  leaf,  or 
contracted  into  a  simple  stipule  or  scale.  According  to 
different  circumstances,  the  self-same  organ  may  be 
developed  into  a  peduncle  or  an  unfruitful  branch.  The 
calyx,  by  over-hastening  itself,  may  become  the  corolla, 
and  conversely,  the   corolla  may  approximate   to   the 

•  AUe  Gestalten  sind  ahnlich.  und  keine  gleichet  der  andem, 
Und  so  deutet  der  Chor  auf  ein  gehcimes  Gesetz, 
Auf  ein  heiliges  Rathsel 


GOETHE.  109 

calyx.  Thus  the  most  varied  structures  of  plants 
are  rendered  possible,  and  he  who  in  his  observations 
keeps  these  laws  always  before  his  eyes  will  derive  from 
them  great  alleviation  and  advantage."  These  fev/  lines 
contain  the  pith  of  the  doctrine  of  the  Metamorphosis 
of  Plants  which  so  greatly  agitated  his  contemporaries 
during  the  first  quarter  of  this  century.  The  many- 
sidedness  of  the  idea  made  it  inevitable  that  the 
notion,  once  grasped,  should  extend  to  the  remainder 
of  the  organic  world.  Before  Goethe,  no  naturalist  had 
regarded  insects  otherwise  than  as  a  given  sum  of  indi- 
vidual forms,  distinguishable  by  certain  definite  charac- 
teristics. Their  internal  structure  had  certainly  been 
disclosed  by  some  few  great  men,  such  as  Malpighi, 
Swammerdam  and  Lyonet,  but  a  real  comparison  of 
species  and  genera  had  never  been  contemplated ;  still 
less  an  explanation  of  the  body  by  its  parts.  This 
Goethe  accomplished,  and  with  true  genius  ;  for  to  his 
theory,  and  with  perfect  truth,  the  rings  which  in  the 
insect  are  ranged  from  the  head  to  the  tail,  presented 
themselves,  like  the  vegetal  organs,  as  mere  modifications 
of  one  and  the  same  rudimentary  organ.  There,  the 
leaf  in  the  abstract,  the  primordial  leaf  or  plant — here 
the  ring. 

With  this — it  was  in  1796,  in  the  discourses  on  the  pro- 
ject of  a  general  introduction  to  Comparative  Anatomy — 
he  enunciated  a  truth  which  was  not  recognized  till  more 
than  forty  years  later,  by  one  of  the  most  distinguished 
zoologists,  Milne  Edwards,  and  applied  to  the  knowledge 
of  the  animal  world.  This  is  the  idea  of  the  develop- 
ment of  organic  beings  by  the  heterogeneous  evolution 
of  their  fundamentally  similar  parts.     Of  this  the  cater- 


no  THE   DOCTRINE   OF   DESCENT. 

pillar  and  butterfly  serve  as  an  example.  "Imperfect 
and  evanescent  a  creature  though  the  butterfly  may  be 
as  to  its  species,  when  compared  to  the  mammal,  in  the 
metamorphosis  which  it  accomplishes  before  our  eyes,  it 
nevertheless  exhibits  the  superiority  of  a  more  perfect 
over  a  less  perfect  animal.  This  consists  in  the  deci- 
siveness of  its  parts,  the  security  that  none  can  be  put 
or  taken  for  the  other;  that  each  is  destined  for  its 
function,  and  remains  constant  to  it  for  ever."  Now, 
however,  in  the  most  perfect  creatures,  the  Vertebrata, 
there  appeared  before  Goethe's  eye,  a  similar  rudimentary 
organ,  metamorphosing  itself  within  the  individual ;  this 
was  the  vertebra.  He  followed  it  in  its  transformations 
along  the  vertebral  column.  Impossible  as  it  may  be, 
by  placing  together  the  first  vertebra  of  the  neck  witii 
the  last  tail  bone  to  infer  their  identity,  it  becomes 
manifest  in  the  gradual  transition. 

But  what  lies  in  front  of  the  first  vertebra  of  the 
neck.^  Is  the  cranium  something  absolutely  different, 
something  new,  not  identical  with  the  vertebral  column  ? 
This  was  another  perturbing  thought  which  pursued 
Goethe's  every  footstep.  He  pondered  and  compared  ; 
it  could  not  be  otherwise  ;  the  cranium  must  beloncf 
to  the  vertebral  column,  must  be  nothing  more  than  a 
part  of  the  vertebral  column.  Through  the  vacillations 
of  his  conceptions,  he  was,  as  he  later  expresses  himself 
on  another  occasion,  "as  an  honest  observer  transported 
into  a  sort  of  frenzy."  Then,  when  in  1790  he  picked 
up  a  bleached  sheep's  skull  in  the  Jewish  cemetery  at 
Venice,  "  the  derivation  of  the  cranium  from  the  verte- 
bral bones  was  revealed  to  him."  The  more  special 
history  of  Comparative  Anatomy  has  shown  how  ex- 


GOETHE.  Ill 

trcmely  fruilful  was  this  supposed  discovery,  although 
the  subject  is  far  more  complex  than  Goethe  and  his 
followers  imagined. 

We  must  commemorate  yet  another  genuine  dis- 
covery made  by  Goethe,  which  exhibits  his  very  peculiar 
method.  It  relates  to  the  intcr-maxillary  bone  in 
man.  About  1780,  he  was  studying  osteology  at  Jena, 
under  the  guidance  of  Loder,  an  anatomist  of  some 
renown.  It  is  evident  that  all  higher  animals  possess 
a  bone,  the  so-called  inter-maxillary  bone,  supporting 
the  upper  incisor  teeth.  "The  strange  case  now  oc- 
curred," relates  Goethe,  "that  the  distinction  between 
apes  and  men  was  made  by  ascribing  an  inter-maxillary 
bone  to  the  former,  and  none  to  the  latter  ;  but  as  this 
part  is  mainly  remarkable  as  the  upper  incisor  teeth  are 
set  in  it,  it  was  inconceivable  how  man  should  have  the 
incisor  teeth  and  lack  the  bone."  It  was  inconceivable 
to  him  because,  from  the  comparisons  of  Nature,  he  had 
framed  the  idea  "  that  all  divisions  of  the  creature, 
singly  and  collectively,  may  be  found  in  all  animals." 
To  make  man  an  exception,  not  to  be  measured  by  the 
same  pattern,  was  repugnant  to  his  mind.  Man  must 
have  an  inter-maxillary  bone ;  and,  contrary  to  the 
opinions  of  the  greatest  anatomists  of  that  period,  such 
as  Peter  Camper,  he  demonstrated  how  in  man  this 
inter-maxillary  bone,  although  it  subsequently  becomes 
almost  undistinguishably  anchylosed  with  the  actual 
supra-maxillary  bone,  nevertheless  exists,  quite  dis- 
tinctly, as  a  separate  part  during  development  and  early 
infancy. 

From  this  narrative  we  have  gained  a  good  deal.  In 
the  contemplation  of   individuals  and  details,  Goethe 


112  THE   DOCTRINE   OF  DESCENT. 

found  no  pleasure.  Nature  and  natural  objects,  as  ex- 
istent and  complete,  merely  inspired  the  wish  forthwith 
to  examine  their  origin  and  its  cause.  To  judge  of 
things  by  their  final  causes,  according  to.  an  assumed 
purpose  pre-determined  by  Providence,  he  deemed  "  a 
melancholy  expedient "  which  must  be  entirely  set  aside. 
For  this  method  of  contemplating  Nature,  as  pursued 
by  him,  in  which  all  living  things  are  to  be  conceived 
as  intrinsically  connected,  the  external  as  an  indication 
of  the  internal  form,  he  created  the  name  of  Morpho- 
logy, the  doctrine  of  form.  He  examined  "how  Nature 
lives  by  creating  ;"  and  from  amazement  at  the  eternal 
formation  and  transformation,  from  the  perplexity  into 
which  he  was  plunged  by  the  manifold  variety  of  forms, 
we  see  him  emerge  by  seeking  and  finding  primordial 
forms. 

Even  before  the  realization  of  the  metamorphoses  of 
plants,  we  find  him  surrounded  by  bones  and  complete 
skeletons  in  his  scientific  ossuary  at  Jena ;  he  thought 
he  had  found  a  lodestar  in  the  erection  of  an  anatomical 
Type^  an  universal  symbol,  "  in  which  the  forms  of  all 
(vertebrate)  animals  were  potentially  contained,  and  by 
which  each  animal  may  be  described  according  to  a 
certain  arrangement."  "  Experience  must  first  teach  us 
which  are  the  parts  common  to  all  animals,  and  wherein 
these  parts  differ.  The  idea  must  control  the  whole, 
and  in  a  genetic  manner  deduce  the  universal  model." 
Thus  by  an  abstract  of  the  individual,  we  are  to  possess 
ourselves  of  a  certain  archetype.  As  man  could  not  be 
taken  as  a  standard  for  animals,  and  conversely,  the  in- 
finite complexity  of  man  could  not  be  fully  explained 
by  animal  organization,  something  fluctuating  between 


GOETHE.  113 

the  two  must  be  summoned  to  solve  the  problem.  To 
this  archetype,  itself  incapable  of  representation, — to 
this  abstraction,  and  to  this  alone, — Nature,  according  to 
Goethe,  was  bound  to  adhere  in  her  work  of  creation, 
"  without  being  able,  in  the  slightest  measure,  to  break 
through  or  overleap  the  circle." 

If  it  be  attempted  to  make  it  appear  that  Goethe 
actually  proclaimed  the  doctrine  of  Descent,  or  was 
even  in  a  poetical  sense  its  inspired  prophet,  either  too 
much  value  is  attributed  to  his  enunciations  of  "cease- 
less progressive  transformation,"  and  such  like,  or  the 
sense  which  he  connected  wdth  them  is  not  appreciated. 
Now  let  us  take  the  following  passage,  which  Haeckel 
looks  upon  as  decisive.  "  Thus  much  we  should  have 
gained  ;  that  we  may  fearlessly  affirm  all  the  more  perfect 
organic  beings,  among  which  we  include  Fishes,  Amphi- 
bians, Birds,  Mammals  (and  at  the  head  of  the  latter, 
Man),  to  be  formed  according  to  an  archetype,  which 
merely  fluctuates  more  or  less  in  its  very  persistent  parts, 
and  moreover,  day  by  day,  completes  and  transforms 
itself  by  means  of  reproduction."  Is  it  here  meant, 
perchance,  that  the  persistent  are  contrasted  with  the 
non-persistent  parts  ?     By  no  means. 

Even  prior  to  GeoiTroy  Saint  Hilaire,  Goethe  had 
spoken  of  a  law,  w^hich  is,  however,  no  law,  nor  even  an 
expression  of  facts,  namely,  that  Nature  in  her  work  has 
to  deal  with  a  given  quantity  of  material  to  which  she 
must  adapt  it  He  does  not  seem  to  have  been  aware 
that  Aristotle  had  affirmed  the  same,  that  Nature,  if 
she  enlarged  an  organ,  did  so  only  at  the  expense  of 
another.  A  second  of  the  supposed  fundamental  laws 
discovered   by   the    Frenchman,    that   an   organ  would 


CI4  THE   DOCTRINE   OF   DESCENT. 

sooner  perish   than   resign   its   place,  was   likewise  in- 
stituted by  him  at  the  same  time. 

Thus,  in  Goethe's  opinion,  nature  always  makes  use 
of  the  same  parts.  Nature  is  inexhaustible  in  the 
niodification  and  realization  of  the  archetype ;  but  to 
that  which  has  once  attained  realization  cleaves  the 
tenacious  power  of  persistency,  a  vis  centripeta,  of  which 
the  profound  basis  is  beyond  the  influence  of  anything 
external.  Hence,  if  he  speaks  of  daily  completion  and 
transformation  by  means  of  reproduction,  he  under- 
stands, with  respect  to  the  animal  which  has  attained 
realization,  merely  that  course  of  development  or  meta- 
morphosis which  is  an  image  of  inexhaustible  pheno- 
menal nature.  The  influences  which  Nature  has  exer- 
cised upon  the  parts,  he  pictures  to  himself  as  still 
present ;  but  of  an  actual  transformation  of  existing 
species  into  new  ones,  such  as  is  required  by  the  modem 
Darwinian  doctrine  of  Descent,  Goethe  does  not  speak 
at  all. 

In  his  view,  what  was  it,  then,  that  was  to  be  trans- 
formed }  Surely  not  the  archetype.  He  says,  indeed, 
*'Thus  the  eagle  fashioned  itself  by  the  air  for  the 
air,  by  the  mountain  top  for  the  mountain  top.  The 
mole  fashions  itself  to  the  loose  soil,  the  seal  to  the 
water,  the  bat  to  the  air  ;"  and  generally,  "  the  animal  is 
fashioned  by  circumstances  to  circumstances."  But  the 
illustrations  which  he  gives  in  the  Sketch  of  A.D.  1796, 
show  plainly  that  he  thought,  not  of  any  transforma- 
tion of  existing  forms,  but  of  mere  modes  of  mani- 
festation of  the  type  and  archetype  as  they  exist  in 
given  species.  He  then  says,  "  The  serpent  stands 
high   m    organization.     It    has   a  decided   head,  with 


GOETHE.  IIS 

a  perfect  auxiliary  organ, — a  consolidated  lower  jaw- 
bone. Only  its  body  is  indefinitely  long ;  and  the 
cause  of  its  being  so  is  that  it  expends  neither  material 
nor  power  upon  auxiliary  organs.  As  soon  as  these 
make  their  appearance  in  another  form,  as,  for  instance, 
in  the  lizard,  though  only  short  arms  and  legs  are  pro- 
duced, the  indefinite  length  must  at  once  contract,  and 
a  shorter  body  takes  its  place.  The  long  legs  of  the 
frog  necessitate  a  very  short  form  for  the  body  of  this 
creature,  and  by  the  same  law,  the  unshapely  toad  is 
laterally  extended."  It  is  well  to  bear  in  mind  this 
somewhat  trivial  passage,  that  we  m^y  not  see  more  in 
the  poetic  glorification  of  the  ^letamorphosis  of  Animals 
than  it  really  contains. 
When  Goethe  says  in  the  magnificent  poem : 

"  Hence,  each  form  conditions  the  life  and  acts  of  the  creature. 
And  each  fashion  of  life,  with  reflex  forcible  action, 
Works  on  the  form :"  * 

it  sounds,  as  we  must  admit,  extremely  seductive.  But 
we  are  sobered,  or  rather  led  to  the  right  standpoint,  by 
reading  his  fascinating  remarks  on  d'Alton's  skeletons 
of  the  rodents  (1824).  It  is  there  made  manifest  that 
Goethe  had  not  the  remotest  idea  of  an  actual  trans- 
formation of  a  rodent  into  any  other  animal  by  the 
force  of  external  influences. 

The  reader  may  judge  for  himself.  **  Let  us  contem- 
plate the  animal  in  the  neighbourhood  of  water ;  as  the 
so-called  water-hog  it  wallows,  pig-like,  on  the  marshy 
shore  ;   as  a  beaver  it  is  seen  building  by  fresh  waters  ; 

•  Also  bestimmt  die  Gestalt  die  Lebensweise  des  Thieres, 
Und  die  Weise  des  Lebens,  sie  wirkt  auf  alle  Gestalten, 
Machtig  zuriick     — 
9 


Il6  THE   DOCTRINE  OF   DESCENT. 

next,  still  requiring  some  degree  of  moisture,  it  burrows 
in  the  earth,  and  at  least  loves  concealment,  hiding  with 
coquettish  timidity  from  man  and  other  animals.  Finally^ 
when  the  creature  arrives  at  the  surface,  it  hops  and 
frisks,  so  that  it  carries  on  its  existence  erect,  and  even 
moves  to  and  fro  on  two  feet  with  marvellous  rapidity. 
Transferred  to  completely  diy  land,  we  at  last  find  the 
decisive  influence  of  the  airy  eminence  and  the  all- 
vivifying  light.  The  animal  is  endowed  with  the  greatest 
ease  of  movement ;  it  acts  and  works  with  consummate 
skill,  until  a  bird-like  motion  passes  into  an  apparent 
flight." 

Thus  does  Goethe  elaborate  the  influence  of  environ- 
ment and  external  conditions  upon  the  modifications  of 
form  ;  it  is  in  vain  to  look  for  the  actual  forms  that  are 
modified.  The  beaver  is  not  transformed  into  the  mouse- 
like burro wer,  the  mouse  into  the  jumping  mouse,  nor 
the  jumping  mouse  into  the  squirrel,  nor  does  the 
latter  become  a  jerboa ;  but  the  "  ceaseless  progressive 
transformation  "  is  perceptible  only  to  the  eye  of  the 
imagination.  In  reality,  moreover,  Goethe  sees  only 
adaptation.  Greatly  as  he  is  inclined  to  attribute 
modifications  to  the  effect  of  external  conditions,  he 
speaks  with  no  less  decision  on  the  contrary  side.  ''The 
parts  of  the  animal,  their  relative  form,  their  conditions, 
their  special  characters,  determine  the  requirements  of 
the  creatures'  existence  ;"  and  if  within  the  restricted 
circle  of  forms,  we  nevertheless  find  that  infinite  modi- 
fications of  form  become  possible  (Sketch,  1796),  this 
is  only  to  be  deduced  from  the  individual  species 
exhibited  as  modifications  of  the  archetype,  by  Nature, 
ever  one  and  ever  creative. 


GOETHE.  117 

With  the  word  Species,  we  reach  the  most  important 
point  in  our  account  of  Goethe's  theory  of  nature  ;  if 
indeed  we  have  not.already  unquestionably  proved  that 
he  can  in  no  way  be  regarded  as  a  true  precursor 
of  Darwin.  Darwin  and  his  adherents  maintain  the 
variabiHty  of  the  so-called  vegetal  and  animal  species. 
The  question  is  simply  whether  Goethe  was  or  was 
not,  like  his  contemporary  Lamarck,  convinced  of  this 
mutability.  If  he  says  on  one  occasion  that  *'from 
the  seed,  plants  are  developed,  ever  diverging  and 
variously  determining  the  mutual  relations  of  their 
parts,"  this  is  ambiguous  in  itself;  it  may  refer  either 
to  the  origin  of  new  species,  or  to  the  variability  of 
species  by  nature  immutable.  Another  time  he  speaks 
of  the  "  purpose  of  Nature  "  in  the  horse. 

I  can  find  but  one  single  passage  in  Goethe's  writings 
in  which  there  is  a  question  of  an  actual  transformation 
of  a  creature,  if  not  into  a  new  species,  at  least  into  a 
very  marked  and  persistent  variety.  In  1820,  a  Dr. 
Korte  gave  a  description  of  a  primaeval  bull  found  in 
the  neighbourhood  of  Halberstadt,  and  instituted  com- 
parisons and  reflections,  how  under  the  influence  of 
domestication  our  highly  modified  cattle  had  been 
evolved  from  the  former.  This  relic,  and  another  in 
Thuringia  (1821),  which  latter  specimen  was  obtained 
by  him  for  the  Museum  at  Jena,  gave  him  an  oppor- 
tunity of  coinciding  with  Korte,  and  of  illustrating  by  an 
actual  incident,  the  possibility  of  this  doubtless  easy 
transformation. 

But  from  this  to  the  transformation  of  species  there 
is  still  a  long  way,  and  Goethe  did  not  traverse  it.  We 
have  just  seen  that  the  idea  of  deriving  single  animals 


fl8  THE  DOCTRINE  OF  DESCENT. 

now  existing  from  extinct  "ancestral  races,"  was  not 
unfamiliar  to  him.  Nor  would  his  remark,  "  For  we 
have  the  most  distinct  remains  of  organic  creatures 
which  were  unable  to  perpetuate  themselves  by  active 
reproduction,"  exclude  his  having  accepted  generally 
the  immediate  connection,  based  on  direct  reproduction, 
of  the  animal  world  with  fossil  races  entirely  differing 
in  structure.  For  it  is  quite  true  that  many  species, 
genera  and  groups,  passed  through,  not  their  prime  only, 
but  also  their  decline  and  total  extinction  antecedent  to 
the  present  era. 

Yet  more.  In  "Aphoristic  Annotations,"  which  he 
terms  problems,  written  previous  to  the  year  1823,  he 
speaks  of  "  characterless  races,  which  it  is  scarcely  per- 
missible to  assign  to  a  species,  as  they  lose  themselves  in 
boundless  varieties,"  and  he  contrasts  them  "  with  races 
possessed  of  a  character,  which  they  exhibit  afresh  in 
all  their  species,  so  that  they  may  be  ascertained  in  a 
rational  method."  Goethe  rests  on  this  fact  to  illustrate 
his  idea  of  metamorphosis ;  and  we  have  no  right  to 
explain  the  characterless  or  "disorderly"  races  in  a 
Darwinian  sense,  as  being  those  of  which  the  forms 
are  not  established,  while  those  which  possess  a  character 
are  divided  into  easily  distinguishable  species,  because  a 
host  of  intermediate  forms  have  succumbed  in  the 
struggle  for  existence.  He  gave  this  problem  to  his 
intelligent  young  friend,  Ernst  Mayer,  that  he  might 
work  it  out,  and  impart  his  reflections  to  his  instructor. 

Mayer  says  :  "  The  more  readily  the  former  (the 
genera  possessing  character)  are  arranged,  the  more 
difficult  it  is  to  dispose  of  the  latter  (those  which  possess 
no  character).     But  any  one   wlio  observes  them  with 


GOETHE,  1 19 

earnestness  and  persevering  zeal,  and  is  not  totally 
deficient  in  intuitive  tact,  cultivated  by  exercise,  far 
from  being  perplexed  by  them,  will  assuredly,  amidst 
all  their  varieties  of  form,  very  soon  detect  the  true 
species  and  their  characters.  But  if  indeed,  in  any  one 
genus  rich  in  forms,  no  limit  to  which  nature  herself 
adheres  should  be  discovered,  what  should  hinder  us 
from  treating  it  as  a  single  species,  and  all  its  forms 
as  so  many  varieties  ?  As  long  as  the  evidence  is 
wanting,  which  it  is  not  likely  will  ever  be  produced, 
that  no  species  whatever  exists  in  nature,  but  that  every, 
even  the  remotest  form,  may  be  evolved  from  the  other 
by  intermediate  links, — till  then  we  must  be  allowed  to 
rely  upon  the  course  already  indicated.  Let  the  master 
now  instruct  the  scholar,  or,  according  to  ancient  custom, 
support  him."  And  he  does  support  him,  for  in  his 
morphological  writings  he  adopts  his  pupil's  enuncia- 
tions on  the  problem  as  a  testimony  of  entire  commu- 
nity of  mind  and  soul. 

There  can  be  no  question  that  Goethe's  thoughts  on 
organic  nature  were  more  profound  than  those  of  his 
contemporaries.  But  we  must  not  forget  that  the  cardi- 
nal idea  of  a  modifiable  archetype  prevailed  among 
eminent  men  both  before  and  with  Goethe,  as  I  have 
shown  in  my  little  work  known  to  the  profession,  "  The 
Development  of  Comparative  Anatomy  "  (Die  Entwick- 
elung  der  vergleichenden  Anatomic,  1855).  If  in  his 
popular  lectures,  Peter  Camper  amused  his  audience  by 
a  diagram  in  which  he  evolved  a  beautiful  female  figure 
from  a  horse  ;  if  he  says  that  he  is  so  entirely  absorbed 
in  studying  the  whale  and  comparing  it  with  the  human 
structure  that  every  girl,  pretty  or  ugly,  appeared  to  him 


120  THE   DOCTRINE   OF   DESCENT. 

like  a  dolphin  or  a  cachelot ;  this  was  because  he  started 
from  an  archetype  or  fundamental  form,  Goethe  was 
only  more  consistent,  and  notwithstanding  the  "  painful 
consequences,"  insisted  on  the  inter-maxillary  bone  in 
man  as  in  the  ape. 

Goethe  says  in  1807  :  *' If  plants  and  animals  be  con- 
templated in  their  most  imperfect  condition,  it  is  scarcely- 
possible  to  distinguish  them.  This  much,  however,  we 
may  say,  that  from  a  kindred  so  close  as  scarcely  to  be 
discriminated,  emerge  creatures  which,  as  plants  and 
animals,  are  perfected  in  two  different  directions,  so  that 
the  plant  finally  attains  its  glory  in  the  tree,  durable 
and  rigid  ;  the  animal  in  man,  in  extreme  mobility 
and  freedom."  But  this  is  nothing  more  than  the  re- 
petition, symbolically  embellished,  in  Goethe's  "method 
of  investigating,  knowing,  and  enjoying,"  of  a  proposi- 
tion already  propounded  by  Buffon  fifty  years  before, 
and  subsequently  varied  in  many  ways. 

Nor  is  it  Goethe  who,  in  his  Sketch  of  1796,  first  urges 
the  very  suggestive  comparison  of  identical  organs  in 
the  same  body  ;  this  was  already  done  by  Vicq  d'Azyr 
in  1786.  In  a  word,  the  conception  of  type,  arche- 
type, ground-plan  {dessein  primitif),  was  an  acquisition 
of  that  age,  which  was  merely  expressed  by  Goethe  in 
a  more  pregnant  and  many-sided  manner,  and  which 
appears  the  more  alluring  as  he  combined  with  it  the 
idea  of  motion  and  mobility,  but,  owing  to  his  excessive 
craving  for  symbols,  he  did  this  in  a  figurative  sense. 

When  Goethe  imagines  that  he  has  discovered  "  laws," 
he  labours  under  the  same  delusion  as  that  in  which 
naturalists  have  rocked  themselves  from  the  last  century 
down  to  the  most  recent  times,  when  they  accept  a  mere 


RICHARD  OWEN.  121 

corroboration  of  facts  for  an  explanation  of  those  facts, 
for  their  reduction  to  their  causes.  He  is  acquainted 
with  a  "spiral  tendency"  and  a  "vertical  tendency"  in 
plants,  and  they  at  once  become  "  fundamental  laws  of 
life."  Now  in  root  and  stem  we  undoubtedly  see 
a  vertical  tendency  downwards  and  upwards  ;  we  see 
convolutions  and  tendrils ;  we  have,  moreover,  been 
able  to  analyze  these  facts  into  simpler  physical  and 
physiological  phenomena,  without  having  arrived  at 
the  innermost  cause,  the  actual  law. 

Goethe's  opinion  as  to  man's  place  in  Nature  is  implied 
in  what  has  been  already  said.  That  he,  a  creature  and 
a  product  of  Nature  should  form  an  exception  to  the 
animal  so  obviously  resembling  him,  he  could  not 
admit.  He  must  remain  therefore  unconditionally  with- 
in the  type,  "  of  which  the  parts  are  perpetually  modi- 
fied in  all  races  and  species  of  animals."  But  we  have 
now,  I  think,  furnished  sufficient  evidence  that  this  and 
similar  enunciations  apply  only  to  the  potential  varia- 
bility of  the  archetype  which  has  found  expression  in 
the  races  and  species.  Hence  man  also  is  to  him  a 
product  allied  to  the  animal,  only  by  the  idea  of  the 
type,  and  not  by  actual  propagation  and  descent.  This 
is  the  solution  which  he  sought  respecting  the  "most 
beautiful  organization."     And  with  this  he  was  content. 

From  Goethe  to  our  contemporary  Richard  Owen 
seems  a  wide  leap.  But  if  it  was  our  object  to  produce 
in  Goethe  a  stage  of  natural  inquiry  which  contents 
itself  with  a  formula  of  the  correlation  of  living  things, 
dazzling  indeed,  but  ultimately  vague,  the  renowned 
English  comparative  anatomist  will  show  us  how  it  is 
possible  to  take  even  the  final  step  and  arrive  at  the 


122  THE- DOCTRINE  OF   DESCENT. 

conclusion  that  consanguinity  is  the  sole  solution  of  the 
similarity  of  species,  and  how,  nevertheless,  by  clinging 
to  miracle  and  dualism,  the  fruit  of  the  truth  just  recog- 
nized, may  be  suffered  to  elude  the  grasp.'^" 

By  the  personal  incitement  of  Cuvier,  under  whom  he 
studied  in  1830,  R.  Owen  endeavoured  to  gain  a  clear 
perception  of  the  basis  of  homologies.  If  Cuvier  had 
derived  the  agreement  of  organs  from  teleology  by 
saying  that  organs  are  alike  because  and  if  they  have 
like  functions  to  perform,  Owen,  in  Goethe's  fashion, 
seized  upon  an  archetype  to  explain  the  existence  of 
uniformity  amid  multiplicity  and  diversity  of  detail. 
The  series  which  repeat  themselves  in  the  organism, 
such  as  the  vertebrae,  and  a  regular  succession  in  the 
organisms  themselves  seemed  to  him  not  comprehensible 
as  miraculous  creations,  but  only  as  the  result  of  natural 
laws  and  operating  causes,  which  produce  the  species  in 
regular  sequence  and  gradual  completion,  such  laws  and 
causes  being  the  servant  of  predetermining  intelligent 
Will." 

As  a  scholar  pre-eminently  familiar  with  the  fossil 
animal  world,  it  could  not  remain  unknown  to  this 
English  naturalist  that  the  more  remote  the  geological 
period,  the  more  general  and  the  less  specialized  is  the 
organization  of  the  species.  He  was  able  to  trace  this 
particularly  in  the  dentition  of  mammals,  and  specially 
also  in  the  condition  of  those  domestic  animals  which 
begin  with  the  earliest  Tertiary  times  and  gradually 
assume  the  ungulate  character.  Thus  to  the  question 
whether  species  originate  by  miracle  or  by  law,  he 
replies  that  he  presumes  the  latter  to  be  in  constant 
operation.     This  "  law "   is.   however,   something  quite 


LAMARCK.  123 

different  from  what  science  is  wont  to  designate  by  that 
name.  Why  does  the  horse  exist  ?  Because  it  was  pre- 
destined and  prepared  for  man  by  the  Deity.^*  This 
is  supposed  to  occur  by  means  of  the  "  derivative  law." 
But  this  again  is  a  word  which  conveys  no  meaning, 
a  phrase  which  implies  that  the  horse  has  become  a 
horse  because  it  was  so  to  be.  The  predecessors  of  the 
horse  modify  themselves  for  the  interest  of  man,  who 
does  not  as  yet  exist,  but  is  already  taken  into  account 
by  the  intelligent  Will. 

These  ancestors  of  the  horse  might  therefore  be 
compared  to  the  sports  of  Nature ;  the  transformation 
takes  place,  not  because  from  inherent  reasons  it  must 
take  place,  but  because  it  so  pleases  the  intelligent  Will. 
W^e  must  beg  to  decline  such  "  natural  laws  "  as  these. 
Owen  says,  "  I  deem  an  innate  tendency  to  deviate  from 
the  parental  type,  operating  through  periods  of  adequate 
duration,  to  be  the  most  probable  nature  or  way  of 
operation  of  the  secondary  law,  whereby  species  have 
been  derived  one  from  the  other.*^  From  the  Ichthyo- 
saurus to  Man,  he  sees  the  connection  of  descent ;  he 
denies  that  the  influence  of  circumstances  is  decisive;  he 
rejects  a  dozen  times  any  sort  of  miracle ;  but  the  next 
moment  he  cleaves  to  miracle  again,  namely,  to  an  innate 
tendency  towards  a  certain  future  development  not  im- 
posed by  circumstances  and  dependent  on  them,  but 
conducive  to  a  special  purpose. 

Thus  deal  the  trimmers,  who,  through  fear  of  conse- 
quences, appease  their  scientific  consciences  with  a  word. 

We  now  come  to  a  courageous  writer,  whose  principal 
work,  "  La  Philosophie  Zoologique,"^  was  overlooked 
and   well-nigh   forgotten    for    half   a   century,  until    it 


124  THE    DOCTRINE   OF   DESCENT. 

was  restored  to  merited  honour  by  Darwin,  but  more 
especially  by  Haeckel,  and  quite  recently  in  France  by 
Ch.  Martins.  This  is  J.  B.  Lamarck,  who  first  formu- 
lated the  doctrine  of  Descent,  and  in  1804  actually 
propounded  all  the  propositions  which  Darwin  has  con- 
structed afresh  and  more  completely.  Lamarck  pro- 
claimed that  it  is  merely  our  limited  powers  of  compre- 
hension that  demand  the  erection  of  systems,  whereas 
all  systematic  definitions  and  gradations  are  of  artificial 
nature.  We  may  be  assured  that  nature  has  produced 
neither  orders,  families,  genera,  nor  immutable  species, 
but  merely  individuals  which  succeed  one  another,  and 
resemble  those  from  whom  they  descend.  But  these 
individuals  belong  to  infinitely  divergent  races,  which 
continue  so  long  as  they  are  unaffected  by  any  cause  pro- 
ducing alteration.  Starting  from  species,  like  ourselves, 
he  demonstrates  their  instability.  From  comparisons  of 
the  facts  of  hybridization  and  the  formation  of  varieties, 
he  inferred  "  that  all  organizations  are  true  productions 
of  Nature,  gradually  evolved  in  the  course  of  a  long  suc- 
cession of  ages  ;  that  in  her  progress.  Nature  began,  and 
even  now  always  begins  again,  with  the  formation  of  the 
simplest  organic  bodies,  and  that  she  directly  forms  these 
only,  namely,  those  lowest  living  beings  which  have  beer- 
designated  as  spontaneous  generations." 

Variations  and  transformations  supervene,  according 
to  Lamarck,  through  external  influences ;  in  the  lapse 
of  ages  they  become  essential  differences  ;  so  that,  after 
many  successive  generations,  individuals  which  originally 
belonged  to  another  species  ultimately  find  themselves 
converted  into  a  new  one.  The  limited  period  of  our 
existence  has  accustomed  us  to  a  standard  of  time  so 


LAMARCK.  125 

short  pi9  to  give  rise  to  the  vulgar  and  false  hypothesis 
of  stabiHty  and  immutability.  The  transformation  is 
effected  by  the  obligation  of  the  individual  to  accom- 
modate itself  to  the  altered  conditions  of  life.  Fresh 
circumstances  elicit  fresh  requirements  and  fresh  activi- 
ties. Great  weight  must  be  laid  on  the  use  or  disuse 
of  organs.  "  In  every  animal  still  in  the  course  of  de- 
velopment, the  more  frequent  and  sustained  use  of  an 
organ  gradually  fortifies,  developes  and  enlarges  it,  and 
endows  it  with  strength  proportional  to  the  duration  of 
this  use  ;  while  the  persistent  disuse  of  an  organ  imper- 
ceptibly weakens  and  deteriorates  it,  diminishes  its  effi- 
ciency in  an  increasing  ratio,  and  ultimately  destroys  it." 
**And  thus,"  he  says,  "nature  exhibits  living  beings 
merely  as  individuals  succeeding  one  another  in  genera- 
tions ;  species  have  only  a  relative  stability,  and  are 
only  transiently  immutable." 

Lamarck  touches  upon  the  struggle  of  each  against  all 
(I.  99,  and  elsewhere),  but  does  not  discover  the  term 
Natural  Selection.  He  is  fully  conscious  of  the  two 
factors,  heredity  and  adaptation,  but  his  theories  and 
convictions  lack  the  emphasis  of  detailed  evidence. 
Yet  his  subtle  apprehension  of  life  may  be  evinced  by 
his  interpretation  of  instinct.  According  to  him,  all 
acts  of  instinct  are  effected  by  incitement,  exercised 
upon  the  nervous  system  by  acquired  inclinations 
{penchaiis  acquis) ;  and  these  acts,  not  being  the  product 
of  deliberation,  choice,  or  judgment,  certainly  and  un* 
erringly  satisfy  the  requirements  experienced  and  the 
inclinations  resulting  from  habit.  But  if  these  inclina- 
tions to  maintain  the  habit  and  renew  the  actions 
related  to  them,  are  once  acquired,  they  are  henceforward 


126  THE  DOCTRINE  OF  DESCENT. 

transmitted  to  the  individuals  by  means  of  reproduc- 
tion, which  maintains  the  structure  and  the  disposition 
of  the  parts  in  the  condition  attained,  so  that  the  same 
inclination  pre-exists  in  the  young  individuals  before 
they  put  it  in  practice.  This  explanation,  as  Darwin 
has  shown,  certainly  does  not  suffice  for  all  the  facts  of 
instinct,  yet  it  stands  far  above  the  modern  "  Philosophy 
of  the  Unconscious "  (Philosophic  des  Unbewussten), 
which  places  the  organisms  by  which  the  instincts  are 
effectuated,  under  the  sway  of  an  extraneous  metaph)- 
sical  Being  who  governs  it  in  subservience  to  design.*^^ 


VII. 


Lyell  aud  Mcxleru  Geology— Darwin's  Theory  of  Selectiuu — Beginning 
of  Life. 

Ever  since  mankind  has  consciously  laboured  in  the 
field  of  intellect,  pre-eminent  men  have  existed,  who, 
reasoning  more  rapidly  than  their  contemporaries,  have 
outstripped  them  in  the  apprehension  of  great  truths 
and  the  recognition  of  important  laws.  But  it  is  a 
great  temptation  to  set  too  high  a  value  on  these  anti- 
cipations ;  and  in  all  cases  in  which  these  intellectual 
exploits  are  concerned,  it  will  be  discovered  that,  so  to 
speak,  they  floated  in  the  air,  and  that  it  was  merely  a 
keener  scent  and  a  so-called  intuition  resting  on  uncon- 
scious inferences,  which  exalted  the  privileged  being 
above  his  less  sharp-sighted  neighbours. 

Great  scientific  crises,  revolutions  in  the  domain  of  in- 
tellect, are  prepared  long  beforehand  ;  the  watch-word 
rarely  comes  too  early  and  is  seldom  pronounced  in 
accents  unintelligible  to  contemporaries ;  as  a  rule,  if 
the  change  has  not  been  altogether  gradual  and  almost 
un perceived,  but  if  on  the  contrary  the  veil  has  been 
suddenly  drawn  aside  by  one  of  these  chosen  spirits, 
scales  fall,  as  it  were,  from  the  eyes  of  fellow-labourers 
and   spectators,   and  the  rapidity  with  which  the  new 


r28  THE  DOCTRINE  OF   DESCENT. 

theory  makes  its  way  affords  the  best  evidence  that  it 
took  shape  and  was  proclaimed  at  the  proper  moment. 

That  the  doctrine  of  Descent  was  likewise  no  utterly 
startling  apparition,  even  though  it  leapt  forth  from  the 
head  of  Darwin,  its  greatest  representative,  like  an  armed 
Minerva — of  this  we  have  cited  at  least  a  few  of  the  many 
vouchers.  That  its  time  had  come, — that  it  was  indeed 
more  than  time,  unless  the  science  of  the  nature  of  life, 
and  Biology  in  general,  was  to  be  unduly  backward, — 
is  shown  by  the  development  of  Geology,  which  thirty 
years  prior  to  Darwin,  after  many  favourable  forecasts, 
struck  upon  the  right  road  to  the  knowledge  of  causes. 
The  doctrine  of  the  formation  and  evolution  of  the 
earth,  especially  in  its  earlier  phases,  during  which  Life, 
in  the  sense  generally  attached  to  the  word,  originated 
and  became  permanent  on  our  Planet, — this  science  of 
Geology  is  intimately  allied  with  our  important  theme. 
Modern  Geology,  especially  as  connected  with  the  name 
of  Charles  Lyell,  must  sooner  or  later  have  necessitated 
an  analogous  treatment  of  vegetal  and  animal  lore,  and 
we  can  only  wonder  that  the  crisis  was  so  long  delayed. 
The  exposition  of  the  doctrine  of  Descent  must,  there- 
fore, be  introduced  and  initiated  by  a  reference,  however 
brief,  to  modern  Geology. 

The  first  edition  of  Lyell's  '*  Principles  of  Geology  " 
appeared  in  1830.  The  tenth,  published  in  1866,  gave  him 
an  opportunity  of  professing  his  full  adhesion  to  the 
Darwinian  doctrines,  to  the  development  of  which  he 
had  given  so  great  an  impulse.  Since  1872,  the  eleventh 
edition  of  this  masterpiece  has  been  before  the  world. 
It  treats  of  the  investigation  of  the  lasting  effects  of 
causes  now  in  operation,  as  data  from  which  inferences 


LYELL  AND  RECENT  GEOLOGY.  *      1 29 

as  to  past  ages  may  be  drawn.  Lyell  termed  these 
effects  an  autobiography  of  the  earth.  "  The  forces 
now  operating  upon  earth  are  the  same  in  kind  and 
degree  as  those  which  in  the  remotest  times  produced 
geological  changes." 

Probably,  in  consequence  of  the  havoc  caused  by  local 
floods  and  earthquakes,  a  belief  in  great  and  universal 
catastrophes  was  formed  at  a  very  early  period  ;  and  to 
the  Indian  and  Egyptian  legends  on  this  subject  Lyell 
appends  the  remark,  that  the  traditional  connection  of 
such  catastrophes  with  a  belief  in  repeated  and  universal 
corruption  of  morals  may  be  easily  explained. 

At  the  end  of  the  last  century,  the  opinion  was  here  and 
there  expressed  that  the  submergence  of  large  extents 
of  land,  and  the  emergence  of  others,  had  taken  place 
slowly ;  and  the  doctrine  was  in  preparation  that  the 
mineral  masses  fall  into  various  groups,  succeeding  one 
another  in  definite  order.  Werner  then  appeared  and 
founded  the  special  science  of  "Geognosy."  He  was 
not  the  first  to  see  and  teach  the  regular  succession  of 
rocks,  but  the  sensation  which  he  caused  was  uni- 
versal. From  his  time  dates  the  violent  controversy  of 
the  Vulcanists  and  Neptunists,  and  into  the  midst  of 
this  controversy  fell  Cuvier's  great  discoveries  on  the 
animals  of  the  Tertiary  formation  in  the  vicinity  of 
Paris.  By  the  works  of  Cuvier  and  Lamarck  on  fossil 
animals,  the  differences  betwixt  ancient  and  modern 
organisms  became  apparent,  and  Cuvier's  views,  zoolo- 
gical as  well  as  geological,  gained  the  victory.  The 
conviction  was  gradually  established  that  long  ages  of 
repose  and  quiescence  alternated  on  earth  with  shorter 
periods  of  universal  catastrophes  and  revolutions/* 


£30  THE   DOCTRINE  OF   DESCENT. 

Even  after  the  appearance  of  Lyell's  **  Principles  of 
Geology,"  the  hypothesis  of  catastrophes  received  its 
special  completion  by  Elie  de  Beaumont's  theory  of  the 
structure  and  genesis  of  mountain  chains.  From  the 
first,  however,  Lyell  interposed,  and  derived  the  following 
conclusion  from  a  comparison  of  the  slow  but  continued 
and  perceptible  upheavals  and  subsidences  occurring 
in  historic  times,  with  the  various  modifications  which 
organisms  had  meanwhile  undergone.  "  In  a  word,  the 
movement  of  the  inorganic  world  is  obvious  and  pal- 
pable, and  might  be  likened  to  the  minute-hand  of  a 
clock,  the  progress  of  which  can  be  seen  and  heard  ; 
whereas  the  fluctuations  of  the  living  creation  are 
nearly  invisible,  and  resemble  the  motion  of  the  hour- 
hand  of  a  time-piece.  It  is  only  by  watching  it  atten- 
tively for  some  time,  and  comparing  its  relative  position 
after  an  interval,  that  we  can  prove  the  reality  of  its 
motion." 

Careful  observation  and  logical  deduction  had  thus 
arrived  at  conclusions  diametrically  opposite  to  the 
assertions  of  Cuvier,  who  inferred  the  geological  catas- 
trophes mainly  from  the  striking  difi"erence  of  successive 
organisms.  While  botanists  and  zoologists  prosecuted 
their  studies  on  Cuvier's  system.  Geology  was  being 
metamorphosed  under  the  hands  of  Lyell  and  his  adhe- 
rents. He  proceeded  from  the  most  tangible  basis. 
That  it  rained  during  the  era  of  the  coal  formation,  as 
it  now  rains,  may  be  seen  by  the  impress  of  rain-drops 
on  the  levels  of  that  formation.  The  actions  of  rivers, 
the  sediments  of  deltas,  previously  neglected,  were  now 
studied,  and  likewise  the  colossal  mud  deposits,  such  as 
are  exhibited  by  the  Nile  and  the  Amazon,  and  also  the 


DARWIN.  131 

destructive  work  of  the  irregular  motions  of  the  sea, 
and  the  partly  destructive,  partly  formative  work  of  its 
regular  currents.  Calculations  were  made  of  the 
ploughing,  grating,  and  grinding  of  glaciers,  of  the 
substances  which  mineral  springs  dissolve  and  deposit, 
of  the  displacements  of  material  effected  by  existing 
asrencies,  of  the  manner  in  which  the  outlines  of  land 
and  sea  are  altered  by  elevation  and  subsidence. 
Similarly,  the  comparison  of  ancient  and  modern  coral 
reefs  and  oyster  banks  showed  that  these  silent  builders 
have  not  changed  their  habits.  In  short,  the  hypo- 
thesis of  extraordinary  events  and  forces,  unheard  of  in 
our  present  era,  seemed  quite  unnecessary ;  time  only, 
and  the  continuous  development  of  the  earth's  crust, 
were  rendered  evident. 

The  stage  for  reiterated  acts  of  new  creation  of  organ- 
isms had  thus  collapsed,  and  the  hypothesis  of  such 
miraculous  new  creations  became  an  anachronism,  for 
which  a  well-merited  end  was  inevitably  prepared  by 
the  appearance  of  Darwin.  With  Darwinism,  the  doc- 
trine of  Descent  is  an  historical  necessity. 

Charles  Darwin  was  born  in  1809,  and,  as  the  Natu- 
ralist attached  to  the  Beagle  in  her  vo}age  round  the 
world,  under  Captain  Fitzroy,  in  1831-7,  he  enjoyed 
an  opportunity  of  accumulating  rich  experiences.  His 
important  work  on  Coral  Reefs  gave  the  first  adequate 
explanation  of  the  phenomena  resulting  from  the  co- 
operation of  geological  movements,  and  the  organic 
agency  of  the  coral  animal ;  his  Monograph  on  Cirri- 
pedes  bears  witness  to  the  exemplary  care  with  which  he 
can  observe  and  systematically  work  out  the  relations  of 
the  minutest  details.     We  make   this   remark,    as  the 


132  THE  DOCTRINE   OF   DESCENT. 

Opponents  of  the  great  inquirer  endeavour  to  suppress 
his  merits  and  authority  by  maintaining  that  he  is  pro- 
perly a  mere  dilettante,  dealing  with  general  abstrac- 
tions,''"' a  stranger  to  the  keen  observation  which  takes 
full  account  of  facts.  How  Darwin  arrived  at  the  idea 
which  has  made  an  epoch  in  science,  he  has  himself 
made  known  in  the  introduction  to  his  first  work  on 
the  doctrine  of  Descent,  namely,  the  "  Origin  of 
Species;"*''^  and  in  more  detail  in  a  letter  to  Haeckel, 
published  by  the  latter  in  his  **  History  of  Creation " 
(Natiirlichen  Schopfungsgeschichte). 

"  Having  reflected  much  on  the  foregoing  facts,  it 
seemed  to  me  probable  that  allied  species  were  de- 
scended from  a  common  ancestor.  But  during  several 
years  I  could  not  conceive  how  each  form  could  have 
been  modified  so  as  to  become  admirably  adapted  to 
its  place  in  nature.  I  began,  therefore,  to  study  do- 
mesticated animals  and  cultivated  plants,  and  after 
a  time  perceived  that  man's  power  of  selecting  and 
breeding  from  certain  individuals  was  the  most  power- 
ful of  all  means  in  the  production  of  new  races.  Having 
attended  to  the  habits  of  animals  and  their  relations  to 
the  surrounding  conditions,  I  was  able  to  realize  the 
severe  struggle  for  existence  to  which  all  organisms  are 
subjected  ;  and  my  geological  observations  had  allowed 
me  to  appreciate  to  a  certain  extent  the  duration  of 
past  geological  periods.  With  my  mind  thus  prepared 
I  fortunately  happened  to  read  Malthus's  "  Essay  on 
Population;"  and  the  idea  of  natural  selection  through 
the  struiig:le  for  existence  at  once  occurred  to  me.  Of 
all  the  subordinate  points  in  the  theory,  the  last  which 
1    understood  was  the  cause   of  the   tendency  in    the 


ARTIFICIAL   SELECTION.  I33 

descendants  from  a  common  progenitor  to  diverge  in 
character."* 

That  organisms  are  variable  and  not  fixed  in  rigid 
forms,  is  a  phenomenon  so  general  that  variability  passes 
current  as  a  self-evident  property  of  organic  existence. 
In  the  next  chapter  we  shall  inquire  how  far  everything 
organic  is  necessarily  subject  to  mutability.  On  the 
existence  of  this  property  rests  the  artificial  breeding, 
or  selection  by  man,  consciously  and  unconsciously 
exercised  from  the  earliest  commencement  of  hunting 
and  agriculture,  of  which,  as  Darwin  says,  "the  impor- 
tance mainly  lies  in  the  power  of  selecting  scarcely 
appreciable  differences,  which  are  nevertheless  found  to 
be  transmissible,  and  which  can  be  accumulated  until  the 
result  is  made  manifest  to  the  eye  of  every  beholder." 
In  the  "  Origin  of  Species,"  as  an  example  of  methodic 
selection  in  the  production  of  breeds,  Darwin  has  chosen 
the  pigeon,  to  the  breeding  of  wdiich  he  zealously  devoted 
himself  for  many  years. 

The  pigeon  is  specially  adapted  to  the  purpose  of 
scientific  observation  of  the  phenomena  of  breeding, 
because,  owing  to  its  monogamic  habits,  it  is  easy  to 
control,  because  it  may  be  brought  in  a  short  time  to 
striking  variations,  because  the  records  of  its  breeding 
are  tolerably  complete,  and,  finally,  because  it  is  one  of 
the  few  domestic  animals  of  which  the  ancestral  stock 
is  scarcely  open  to  a  doubt. 

The  chief  races  produced  by  the  fanciers  may  be 
grouped  as  follows.  The  Pouter  Pigeons  have  a 
moderate  beak,   elongated  legs    and    body,    their   ceso- 

*  Mr.  Darwin  has  himself  been  good  enough  to  re-write  his  letter  from  the 
German  tevt.     He  kept  no  copy  of  the  original  M 


134  THE  DOCTRINE  OF  DESCENT. 

phagus  IS  of  great  size,  barely  separated  from  the  crop, 
and  is  capable  of  inflation.  A  second  group  includes 
Carriers,  Runts,  and  Barbs,  which  possess  in  common 
a  long  beak,  with  the  skin  over  the  nostrils  swollen 
and  often  carunculated  or  wattled,  and  the  skin  round 
the  eyes  bare  and  likewise  carunculated.  To  another 
group,  with  shorter  beak,  and  the  skin  round  the  eyes 
only  slightly  developed,  belongs  the  Fantail,  in  which 
the  normal  number  of  twelve  tail  feathers  may  rise  to 
forty-two  with  aborted  oil-gland ;  also  the  Tumbler,  in 
which  the  beak  becomes  extremely  short,  and  a  sickly 
disposition  of  the  brain,  produced  and  exaggerated  by 
selection,  and  manifesting  itself  by  tumbling,  has  been 
transmitted  for  more  than  250  years,  and  has  become 
established  as  the  characteristic  of  a  race.  In  the  fourth 
group,  the  Trumpeter  occupies  a  prominent  position,  on 
account  of  its  peculiar  voice  ;  likewise  the  Laugher,  or 
Indian  turtle-dove,  comprising  several  sub-races  scarcely 
differing  in  structure  from  the  rock-pigeon  (Columba 
livia).  The  latter  is  divided  into  several  geographically 
distinct  races,  ranging  from  the  coasts  of  the  Faroe 
Islands  and  Scotland  to  the  shores  of  the  Mediter- 
ranean and  to  India ;  and  the  most  minute  investi- 
gation, whether  the  incredibly  divergent  races  of 
domestic  pigeons  are  derived  from  eight  or  nine  wild 
species  or  solely  from  the  wide-spread  rock  pigeon, 
results  decidedly  in  favour  of  the  latter  alternative. 
Proportional  dimensions,  colouring,  and  parts  of  the 
skeletons  which  differ  from  one  another  far  more  widely 
in  the  various  races  than  they  do  in  well  marked  species 
of  the  same  genus,  or  even  family,  are  modified  under 
die  hand  and  according  to  the  will  of  man ;  and,  more- 


ARTIFICIAL  SELECTION.  1 35 

over,  pre-eminently  in   the  pigeon  may  be  traced   the 
phenomenon  which  has   been  termed  the  "correlation 
of  growth,"  and  consists  in  the  fact  that,  with  the  in- 
tentional modification  of  an  organ  by  means  of  selection, 
one  or  more  other  organs  are  drawn  into  sympathy  and 
unintentionally  transformed  into  characteristics  of  a  race. 
Darwin's  minute  researches  on  the  formation  of  races 
in  the  pigeon  are  recounted  in  his  second  work  on  the 
theory  of  Descent,  "The  Variation  of  Animals  and  Plants 
under  Domestication,"  in  which  the  most  detailed  investi- 
gations respecting  other  domestic  animals  are  also  to  be 
found.     Whoever  has  had  occasion  to  inspect  one  of  the 
modern  exhibitions  of  poultry,  must  have  been  astonished 
at  the  diversity  of  the  different  races,  and  the  purity  and 
uniformity  within  each  race.     Though  not  quite  so  posi- 
tively as  in  the  case  of  the  pigeon,  yet  with  approximate 
certainty,  the  domestic  fowl  appears  to  be  derived  from 
a  single  ancestral  stock,  the  Indian  Gallus  Bankiva.    The 
cumulative  power  of  selection  by  man  is  likewise  testified 
by  the  various  races  of  pigs  bred  within  the  last  century 
by  the  English  farmers  from   an    intermixture  of  the 
native  and  Indian  races,  differing  in  general  appearance, 
colouring,  size  of  ears,  length  of  legs,  and  also  partially 
in  fertility.     Our  attention   is,  however,    more   closely 
drawn  to  the  two  races  of  Southdown  sheep  and  Short- 
horn cattle,  which,  as  well  as  the  choicest  breeds  of  pigs, 
have  been  for  some  years  past  particularly  esteemed  on 
the  continent.     These  and  many  other  races  have  been 
bred  with  definite  purposes,  and  for  certain  domestic  and 
commercial  advantages,  and  one  and  all  bear  testimony 
to  the  plasticity  of  species. 

Artificial  selection  operates  by  establishing  peculiarities 


136  THE  DOCTRINE  OF  DESCENT. 

originally  variable,  and  on  their  first  accidental  appear- 
ance usually  perceived  only  by  the  careful  eye  of  a 
connoisseur.  But  not  a  few  cases  are  likewise  certified 
in  which  an  accidental  deformity  and  a  new  character 
appearing  suddenly  even  in  a  single  individual  have  lent 
themselves  to  the  rapid  formation  of  a  race.  "  Thus," 
as  Darwin  relates,*'  "in  1791  a  ram  lamb  was  born  in 
Massachusetts,  having  short,  crooked  legs  and  a  long 
back  like  a  turnspit  dog.  From  this  one  lamb  the  otter 
or  ancon  semi-monstrous  breed  was  raised  ;  as  these 
sheep  could  not  leap  over  the  fences,  it  was  thought  that 
they  would  be  valuable  ;  but  they  have  been  supplanted 
by  merinos,  and  thus  exterminated.  These  sheep  are 
remarkable  from  transmitting  their  character  so  truly, 
that  Colonel  Humphreys  never  heard  of  but  one  ques- 
tionable case  of  an  ancon  ram  and  ewe  not  producing 
ancon  offspring." — "  A  more  interesting  case  has  been 
recorded  in  the  Report  of  the  Juries  for  the  Great  Exhi- 
bition (185  i),  namely,  the  production  of  a  merino  ram 
lamb  on  the  Mauchamp  farm  in  1828,  which  was  remark- 
able for  its  long,  smooth,  straight,  and  silky  wool.  By 
the  year  1833,  Mr.  Graux  had  raised  rams  enough  to 
serve  his  whole  flock,  and  after  a  few  years  more  he  was 
able  to  sell  stock  of  his  new  breed.  So  peculiar  and 
valuable  is  the  wool,  that  it  sells  at  25  per  cent,  above 
the  best  merino  wool  ;  even  the  fleeces  of  half-bred 
animals  are  valuable,  and  are  known  in  France  as  the 
Mauchamp  merino.  It  is  interesting,  as  showing  how 
generally  any  marked  deviation  of  structure  is  accom- 
panied by  other  deviations,  that  the  first  ram  and  his  off- 
spring were  of  small  size  with  large  heads,  long  necks, 
narrow   chests,  and    lon:^  flanks;    but    these   blcmishca 


UNCONSCIOUS  SELECTION.  1 37 

were  removed  by  judicious  crosses  and  selection.  The 
long,  smooth  wool  was  also  correlatad  with  smooth  horns; 
and  as  horns  and  hair  are  homologous  structures,  we  can 
understand  the  meaning  of  this  correlation.  If  the 
Mauchamp  and  the  ancon  breeds  had  originated  a  cen- 
tury or  two  ago,  we  should  have  had  no  record  of  their 
birth,  and  many  a  naturalist  would,  no  doubt,  have 
insisted,  especially  in  the  case  of  the  Mauchamp  race, 
that  they  had  each  descended  from  or  been  crossed  with 
some  unknown  aboriginal  form." 

If  with  the  refined  culture  of  races  on  large  estates, 
we  compare  the  slight  attention  bestowed  on  domestic 
animals  in  small  peasant  farms,  remote  from  the  cheering 
intercourse  of  the  world,  and  then  descend  to  the  treat- 
ment by  savages  of  their  few  domestic  animals,  or  their 
sole  tame  creature,  the  dog,  conscious  artificial  selection 
gradually  decreases ;  but  wherever  man  attaches  to  his 
abode  either  plants  or  animals,  selection  is  at  least 
unconsciously  exercised.  The  powerful  animal,  the  par- 
ticular plant  which  yields  the  most  abundant  nutriment, 
are  employed  for  propagation  without  any  special  fore- 
thought, and  unconscious  selection  is  thus  undistinguish- 
able  from  that  which  is  methodically  practised.  The 
initiation  and  progress  of  the  production  of  races  is 
naturally  facilitated  by  the  power  of  placing  the  animals 
selected  for  breeding,  in  a  new  environment  and  fresh 
conditions  of  life,  and  the  formation  of  new  races  is 
favoured  by  the  ease  with  which  it  is  possible  to  hinder 
the  crossing  of  forms  in  course  of  construction,  with  races 
already  existing. 

Unquestionably  many  races  of  domestic  animals  are 
not  in  a  condition  in   v/hich  they  can  be  termed  new 


138  THE  DOCTRINE   OF   DESCENT. 

species ;  that  is  to  say,  in  regard  to  the  new  characters 
evolved  by  breeding,  they  are  in  a  state  of  merely  artificial 
stability ;  and,  if  abandoned  to  accidental  or  irregular 
intermixture  with  the  aboriginal  or  other  races,  they 
gradually  revert  to  their  primitive  form.  But  it  is  ar- 
bitrary and  erroneous  to  assert  that  all  unconsciously 
or  consciously  bred  races,  without  exception,  are  no  new 
species,  and  would  all  relapse  if  left  to  a  state  of  nature. 

Granting  that  all  the  races  of  fowls  were  left  to  them- 
selves, we  must  certainly  admit  the  possibility  that  in 
India  some  few  forms  would  change  back  into  the  Bankiva 
fowl.  It  is,  however,  evident  that,  in  Europe  and  America, 
from  any  semi-feral  races  of  fowls  the  aboriginal  Indian 
race  would  never  reappear,  but  at  the  most  some  few  new 
wide-spread  mongrel  forms  would  arise,  remaining  con- 
stant according  to  geographical  districts.  No  one  has 
yet  been  able  to  assert  that  the  wild  dogs  of  the  East, 
entirely  released  from  the  control  of  man,  have  become 
wolves  or  jackals,  their  presumptive  ancestors.  They 
become  "jackal-like,"  by  which  every  one  expresses  that 
the  dog  which  became  and  was  bred  a  domestic  animal 
thousands  of  years  ago,  preserves  its  acquired  specific 
characteristics  even  under  circumstances  most  favour- 
able to  their  destruction. 

This  statement,  that  domestic  animals  are  no  new 
species,  is  the  more  unfounded,  as  of  several  domestic 
animals  the  aboriginal  stock  is  totally  unknown  ;  among 
these  are  the  sheep  and  goat,  respecting  the  ancestors 
of  which  only  vague  conjectures  can  be  framed.  The 
most  ancient  race  of  sheep  known  to  us, — that  with  ram- 
like horns,  found  among  the  lake  dwellings  of  Switzer- 
land, throws  no  light  upon  the  subject;  and  empirically 


NATURAL  SELECTION.  139 

to  observe  t!ie  reversion  of  the  modern  sheep  to  its 
aboriginal  form  is  utterly  impossible.  That  the  horse 
is  derived  from  a  striped  aboriginal  species  is  probable; 
but  notwithstanding  the  many  generations  during  which 
the  great  herds  of  feral  horses  in  South  America  have 
propagated  themselves  undisturbed,  no  such  species 
has  been  produced.  Riitimeyer's  minute  researches  on 
domestic  cattle  have  shown  that,  in  Europe  at  least, 
three  well-Jefined  species  of  the  Diluvial  period  have 
contributed  to  their  formation,  Bos  primigenius,  longi- 
frons,  and  frontosus.  These  species  once  lived  geo- 
graphically separate,  but  contemporaneously ;  and  they 
and  their  specific  peculiarities  have  perished,  to  rise 
again  in  our  domestic  races.  These  races  breed  to- 
gether with  unqualified  fertility ;  in  the  form  of  skull 
aiid  horns  they  recall  one  or  other  of  the  extinct 
species ;  but  collectively  they  constitute  a  new  main 
species.  That  from  their  various  breeds,  the  three  or 
any  one  of  the  aboriginal  species  would  ever  emerge  in 
a  state  of  pristine  purity,  v/ould  be  an  utterly  ludicrous 
assertion. 

In  all  these  domestic  animals — dog,  sheep,  goat,  horse, 
and  cattle — the  transformation  was  initiated  in  an  era  of 
civilization  in  which  there  was  no  idea  of  artificial  breed- 
ing in  the  modern  sense,  and  in  which  the  main  factor  of 
transformation,  independently  of  involuntary  and  uncon- 
scious selection,  consisted  simply  in  the  altered  mode 
of  life.  This  introduces  us  to  variations  in  a  state  of 
nature,  and  to  Natural  Selection.  Natural  as  well  as 
artificial  selection  both  rest  on  the  undisputed  fact  of 
the  idiosyncrasies  of  the  most  closely  allied  vegetal  and 
animal  individuals;  and  it  has  already  become  manifest 


I40  THE  DOCTRINE  OF  DESCENT. 

that  doubtful  species  are  not  exceptional,  as  the  old 
school  was  wont  to  imagine,  but  that  it  is  merely  owing 
to  an  inadequate  knowledge  of  the  material  out  of  which 
species  are  constructed,  that  all  species  are  not  looked 
upon  as  doubtful  and  artificial. 

Let  us  here  again  call  to  mind  that  in  many  thou- 
sand cases  the  most  rigid  systematizers  are  unable 
to  state  where  their  species  begin  and  end  ;  of  which 
Darwin,  as  an  instance,  cites  a  communication  by 
H.  C.  Watson,  that  182  British  plants,  usually  regarded 
as  varieties,  have  each  been  claimed  as  independent 
species  by  individual  botanists.^^  Darwin's  immortal 
service  consists  in  having  shown  what  is  the  power 
which  operates  upon  the  existing  variable  individuals 
and  species,  and  what  results  this  operation  must  pro- 
duce. He  found  the  key  in  the  word  which  has  become 
a  badge  and  common  property  of  our  age,  "  the  struggle 
for  life,"*  and  has  thus  given  the  foundation  and  theory 
of  a  doctrine  of  which  the  truth  had  long  before  been 
manifest  to  an  intellect  such  as  that  of  Lamarck.  He 
founded  the  doctrine  of  Descent  on  the  theory  of  selec- 
tion, when  he  proved  that  in  nature  the  struggle  for 
existence  occasions  a  selection  of  the  best  and  fittest, 
comparable  to  artificial  breeding,  and  giving  rise  to  new 
races  and  new  species. 

The  struggle  for  life,  this  bellum  omnuLiii  contra 
oimieSy  is,  moreover,  an  undisputed  and  undeniable  fact, 
which  we  here  accept  in  its  widest  relations.  Not  only 
does  the  beast  of  prey  war  against  the  graminivorous 
animals,  which  again  strive  to  keep  their  balance  hy 
superior  multiplication,  speed,  and  cunning;  the  gradual 

•  For  Wallace's  share  in  this  honour,  see  the  end  of  this  chapter. 


THE  STRUGGLE  FOR  EXISTENCE.  I4I 

advance  of  a  plant  is  likewise  a  struggle  with  natural 
obstacles;  and  the  conquest  which  it  gains  usually  injures 
other  plants  in  their  conditions  of  life.  If  the  powers 
of  multiplication  of  any  given  organism  were  to  operate 
absolutely  and  unrestrictedly,  each  being  would,  in  a 
short  series  of  years,  claim  for  itself  the  whole  surface  of 
the  earth,  or  all  the  waters  of  the  sea.  But  each  holds 
the  other  in  check ;  and  with  the  living  foes  of  each 
creature  are  associated  the  climate  and  all  the  influences 
of  the  surrounding  conditions,  and  of  the  alternation  of 
the  seasons,  to  which  the  body  must  accommodate  itself. 
Organisms  live  only  at  the  cost  of,  and  for  the  profit  of, 
others ;  and  the  peace  and  quiet  of  nature  sung  by  the 
poet  is  resolved  under  the  searching  eye  into  an  eternal 
disquiet  and  haste  to  assert  and  maintain  existence, 
amid  which  it  is  only  the  thought  of  the  visible  and 
necessary  progress  that  can  rescue  the  observer  from  a 
pessimist  view  of  the  world. 

The  simplest  examples  of  the  relations  of  mutual 
dependence  of  living  beings  are,  however,  the  best  and 
most  conclusive ;  but  the  vast  consequences  depending 
on  circumstances  and  connections  apparently  insignifi- 
cant, and  the  extreme  complexity  of  the  mechanism  by 
which  equilibrium  is  maintained,  have  been  exhibited  by 
Darwin  in  some  examples,  which,  frequently  as  they  have 
been  repeated,  we  shall  also  allow  ourselves  to  reproduce. 
Whereas,  to  the  South  and  North  of  Paraguay  feral  cattle, 
horses,  and  dogs  abound  in  profusion,  they  are  wanting 
in  Paraguay  itself  "Azara  and  Rengger  have  shown  that 
this  is  caused  by  the  greater  number  in  Paraguay  of  a 
certain  fly,  which  lays  its  eggs  in  the  navels  of  these 
animals  when  first  born.    The  increase  of  these  flies,  nu- 


142  THE  DOCTRINE  OF   DESCENT. 

merous  as  they  are,  must  be  habitually  checked  by  some 
means,  probably  by  other  parasitic  insects.  Hence  if 
certain  insectivorous  birds  were  to  decrease  in  Para- 
guay, the  parasitic  insects  would  probably  increase,  and 
this  would  lessen  the  number  of  the  navel-frequenting 
flies ;  then  cattle  and  horses  would  become  feral,  and 
this  would  certainly  greatly  alter  (as  indeed  I  have 
observed  in  parts  of  South  America)  the  vegetation, 
and  this,  again,  would  largely  affect  the  insects,  and 
this  the  insectivorous  birds,  and  so  on,  in  ever-increas- 
ing circles  of  complexity." 

Another  example  out  of  Darwin's  store  is  perhaps  even 
more  striking.  "  I  find  from  experiments  that  humble- 
bees  are  almost  indispensable  to  the  fertilization  of  the 
heartsease  (Viola  tricolor),  for  other  bees  do  not  visit  this 
flower.  I  have  also  found  that  the  visits  of  bees  are 
necessary  for  the  fertilization  of  some  kinds  of  clover ; 
for  instance,  20  heads  of  Dutch  clover  (Trifolium  repens) 
yielded  2,290  seeds,  but  20  other  heads,  protected  from 
bees,  produced  not  one.  Again,  1 00  heads  of  red  clover 
(T.  pratense)  produced  2,700  seeds,  but  the  same  number 
of  protected  heads  produced  not  a  single  seed.  Humble- 
bees  alone  visit  red  clover,  as  other  bees  cannot  reach 
the  nectar.  It  has  been  suggested  that  moths  may  fer- 
tilize the  clovers  ;  but  I  doubt  whether  they  could  do  so 
in  the  case  of  the  red  clover,  from  their  weight  not  being 
sufficient  to  depress  the  wing-petals.  Hence  we  may 
infer  as  highly  probable  that,  if  the  whole  genus  of 
humble-bees  became  extinct  or  very  rare  in  England, 
the  heartsease  and  red  clover  would  become  very  rare 
or  wholly  disappear.  The  number  of  humble-bees  in 
any  district  depends  in  a  great  degree  on  the   number 


THE   STRUGGLE  FOR  EXISTENCE.  I43 

of  field-mice,  which  destroy  their  combs  and  nests  ;  and 
Colonel  Newman,  who  has  long  attended  to  the  habits 
of  humble-bees,  believes  that  more  than  two-thirds  of 
them  are  thus  destroyed  all  over  England.  Now,  the 
number  of  mice  is  largely  dependent,  as  every  one 
knows,  on  the  number  of  cats  ;  and  Col.  Newman  says, 
*  Near  villages  and  small  towns  I  have  found  the  nests 
of  humble-bees  more  numerous  than  elsewhere,  which  I 
attribute  to  the  number  of  cats  that  destroy  the  mice. 
Hence  it  is  quite  credible  that  the  presence  of  a  feline 
animal  in  large  numbers  in  a  district  might  determine, 
through  the  intervention  first  of  mice  and  then  of  bees, 
the  frequency  of  certain  flowers  in  that  district*  '* 

The  closer  the  kindred  of  the  competitors,  the  more 
ardent  is  the  struggle  for  the  existence  ;  for  the  more 
adjacent  organisms  differ  in  their  requirements,  the  less 
do  they  interfere  with  one  another,  and  the  more  will 
each  be  able  to  exhaust  the  resources  of  the  vicinity  for 
its  own  benefit.  This  seems  to  be  flatly  contradicted 
by  the  great  series  of  associated  plants  and  animals ; 
but  on  closer  inspection  they  also  form  no  exception  to 
the  rule,  as,  often  by  their  very  number  they  render 
existence  possible  and  easy  to  one  another,  and  increase 
exactly  in  the  degree  permitted  by  the  stock  of  nutri- 
ment. If  among  associated  plants  or  gregarious  animals 
a  surplus  production  occurs,  competition  and  conflict  in- 
stantly commence,  and  life  is  regulated  in  every  respect 
exactly  as  in  species  less  remarkable  for  the  number  of 
individuals. 

Our  proposition  that  the  vehemence  of  the  struggle 
rises  with  the  closeness  of  the  kindred,  is  thus  univer- 
sally valid.     Such  a  rapid  war  of  extermination  is  rarely 


144  THE   DOCTRINE   OF   DESCENT. 

waged  as  that  between  the  black  rat  (Mus  rattus)  and 
the  brown  rat  (Mus  decumanus);  and  we  far  more 
frequently  imagine  that  harmonious  intercourse  exists 
between  the  members  of  the  same  species  sharing 
the  same  habitation,  as,  for  instance,  hares  or  deer, 
than  that  they  are  anxiously  striving  to  maintain  exist- 
ence. Yet  this  is  not  the  case.  The  two  great  motive 
powers,  the  preservation  of  the  individual  and  the  pre- 
servation of  the  species,  are  unremitting  instigations  to 
v^^arfare,  and  under  their  influence  every  living  being, 
plants  inclusive,  joins  in  conflict  with  its  congeners  of 
the  immediate  vicinity. 

In  this  competition  for  nutriment,  combined  with 
defence  against  all  possible  enemies  and  other  rivals 
for  the  remaining  privileges  of  existence,  the  strongest 
gains  the  advantage,  or  the  most  crafty,  the  most 
skilful — in  short,  the  one  that  can  measure  itself  against 
its  rivals  armed  with  any  sort  of  superiority.  Not 
only  in  the  struggle  for  mates,  but  on  every  occasion 
of  competition,  the  weaker  individuals  are  beaten  off, 
and  a  selection  of  the  strongest  and  the  best  takes  place. 
But  the  primarily  slight, — often  scarcely  perceptible,  ad- 
vantages, mental  as  well  as  bodily,  which  aided  these  in- 
dividuals to  conquer  and  survive  the  other  members  of 
the  species  who  were  weaker  and  destitute  of  accidental 
advantages,  have  a  prospect  of  being  transmitted,  and 
in  the  following  generations  of  becoming  established 
and  increased  by  repeated  selection.  This  selection  is 
therefore  a  natural  and  necessary  course  of  things  ;  and 
it  applies,  not  in  a  merely  general  and  vague  manner, 
as  in  the  external  habit,  size,  and  strength  of  the  indi- 
vidual, but,  owing  to  the  actual  variability  and  plasticity 


SEXUAL  SELECTION.  I45 

of  the  organic  morphological  constituents,  single  parts 
and  organs  may  be  modified  and  perfected  in  definite 
advantageous  directions,  so  as  to  secure  for  the  race  and 
species  a  higher  position  in  the  surrounding  world. 

Besides  the  general  results  of  the  right  of  the  strongest, 
another  very  influential  phenomenon  comes  into  play 
where  the  desire  for  propagation  is  concerned,  which 
Darwin  has  designated  as  "  sexual  selection,"  and  elabo- 
rated in  great  detail  in  his  work  on  the  "  Descent  of 
Man."  In  this  we  must  consider,  first,  the  formation  of 
sexual  peculiarities  in  the  males,  and  the  secondary 
characters  by  which  they  are  aided  in  the  courtship  of 
the  females  ;  and  only  secondly  the  reactions  of  these 
peculiarities  on  the  alteration  and  progress  of  the  species 
in  general. 

The  fundamental  idea  of  Darwin's  theory  of  selection 
is  therefore,  that  the  cumulative  power  of  selection 
exercised  by  man  in  the  breeding  of  races,  is,  in  nature, 
replaced  by  the  struggle  for  life ;  and  that  in  the  course 
of  time,  by  the  cumulation  of  advantages  primarily 
slight  and  becoming  more  and  more  prominent,  lower 
organisms  are  converted  into  higher  ones.  The  process 
is  incessant.  "It  may  be  metaphorically  said,  that  na- 
tural selection  is  daily  and  hourly  scrutinizing  through- 
out the  world  the  slightest  variations,  rejecting  those 
that  are  bad,  preserving  and  adding  up  all  that  are 
good  ;  silently  and  insensibly  working,  whenever  and 
wherever  opportunity  ofi*ers,  at  the  improvement  of  each 
organic  being  in  relation  to  its  organic  and  inorganic 
conditions  of  life."  ** 

The  following  chapters  will  introduce  us  more  nearly 
to  this  theory,  its  truth,  possibility,  application,  and  con- 


146  THE   DOCTRINE  OF   DESCENT. 

firmation ;  meanwhile  we  will  at  once  make  ourselves 
acquainted  with  some  of  the  objections  offered  to  it, 
either  to  the  theory  of  selection  in  particular,  or  to  the 
theory  of  selection  combined  with  the  doctrine  of  trans- 
formation as  a  whole  ;  the  most  important  of  which 
Darwin  has  already  considered  and  answered. 

If,  so  it  is  said,  all  living  beings  stand  in  distinct  and 
uninterrupted  connection  with  one  another,  what  has 
become  of  the  infinitely  numerous  intermediate  forms 
which  must  necessarily,  have  existed  ?  Our  eyes  turn 
first  to  the  organisms  now  living,  and  as,  in  accordance 
with  the  theory,  they  are  assumed  to  be  the  terminal 
twigs  of  an  infinitely  ramified  tree,  which  must  obviously 
press  hard  upon  one  another,  and  must  each  indepen- 
dently diverge  in  all  directions  as  varieties,  we  ask  for 
the  interm.ediate  forms  of  the  species  now  existing  side 
by  side. 

We  may  now  appeal  to  the  evidence  already  given 
(p.  92.  &c.),  that  in  complete  and  extensive  groups  of 
organisms,  modern  scientific  research  has  been  able  to 
discern  nothing  else  than  intermediate  forms.  Similarly, 
the  journey  undertaken  by  Kerner  in  his  little  book  on 
"  Good  and  Bad  Species,"  in  company  with  the  botanist 
Simplicius,  from  the  West  of  Europe  to  the  East,  will 
furnish  an  amusing  number  to  the  reader  eager  for 
further  material.  The  extension  of  the  various  species 
of  Cytisus  which  this  naturalist  has  minutely  investigated, 
likewise  exhibits  the  uninterrupted  existence  of  connect- 
ing forms  on  the  territorial  boundaries  of  species  of  which 
the  centres  of  propagation  are  more  or  less  remote. 
From  all  these  instances,  which  may  be  reckoned  by 
diousands,  it  may  be  inferred  that  a  large  proportion 


DEFICIENCY  OF  TRANSITIONAL  FORMS.  I47 

are  in  a  phase  of  relative  stability.  That  for  this  reason 
their  intermediate  forms  must  be  looked  only  for  in  the 
past,  is  as  little  surprising  ;  it  in  no  way  impugns  the 
truth  of  the  doctrine  of  Descent ;  and  the  demand  for 
intermediate  forms  between  these  local  and  temporarily 
stable  forms  merely  proves  how  little  those  who  make  it 
hive  appreciated  the  nature  of  Descent. 

But  the  objection  mainly  concerns  those  intermediate 
forms  by  which  the  species  are  connected  with  the 
aboriginal  species  preceding  them  in  order  of  time. 
According  to  the  theory,  the  species  now  living  are 
connected  with  the  aboriginal  species  by  forms  identical 
in  quality  with  varieties,  the  "  species  in  process  of 
formation ;"  the  aboriginal  species  with  others  still 
more  ancient,  and  so  on  ;  so  that  an  infinite  number 
of  forms  must  have  existed.  We  have  already  shown 
(p.  97,  &c.)  that  in  an  excess  of  zeal  palaeontologists  have 
set  up  species,  also  to  be  reckoned  by  thousands,  where 
merely  transitional  forms  and  varieties  actually  existed  ; 
we  have  mentioned  that  a  number  of  distinguished 
palaeontologists  of  the  present  day  are  endeavouring  to 
remedy  the  errors  of  their  predecessors,  and  to  exhibit 
the  uninterrupted  transitional  series  from  the  lower  to 
the  more  recent  strata,  where  the  others  with  lavish  in- 
genuity imagined  they  had  discerned  specific  characters. 
Still  it  must  be  admitted  that  the  amount  of  transitional 
forms  as  yet  actually  found  are  a  vanishing  quantity, 
as  compared  with  the  countless  multitude  which  must 
have  existed. 

But  this  deficiency  may  be  satisfactorily  explained.  We 
know  only  a  very  small  proportion  of  the  fossiliferous 
strata,  and,  with  as  much  justice  as  Lamarck  in  the  be- 


i^S  THE   DOCTRINE  OF   DESCENT. 

ginning  of  this  century,  we  may  point  even  now  to  the 
poverty  of  the  collections.  Wherever  the  palaeontolo- 
gist now  lays  his  hand  he  finds  intermediate  forms,  and 
day  by  day  the  material  accumulates  as  it  is  required. 
Nevertheless,  too  much  is  demanded,  and  the  conditions 
of  preservation  are  misunderstood,  if  it  be  supposed 
that  all  intermediate  forms  that  ever  existed  were,  by 
their  bodily  constitution,  either  wholly  or  partially 
adapted  to  preservation,  and  must  therefore  have  been 
actually  preserved.  On  the  contrary,  the  greater  number 
have  assuredly  vanished  without  a  trace.  At  least  half  of 
all  geological  deposits  have  been  destroyed  again  during 
slow  upheavals.  For  from  the  time  at  which  a  sea- 
bottom  formerly  lying  at  a  profound  depth,  with  its 
well-preserved  enclosures,  is  again  raised  within  the 
reach  of  superficial  movements,  it  may  be  crumbled  and 
corroded,  and  the  fossils  contained  in  it  now  share  the 
fate  which  usually  befalls  the  remains  of  the  denizens  of 
flat  shores,  they  are  triturated  by  the  surf. 

To  this  must  be  added  the  important  consideration  that 
the  forms  by  which  the  transition  is  effected  will  mostly, 
not  as  individual.!,  but  as  forms,  have  had  a  briefer  period 
of  existence  than  the  persistent  varieties  appearing  to  us 
as  species,  as  may  be  seen,  among  other  instances,  in 
the  instructive  discoveries  at  Steinheim.  In  this  parti- 
cular, the  periods  of  transition  from  one  geological  plane 
to  the  next,  resemble  the  boundary  regions  of  two  geo- 
graphical districts.  The  tract  of  transition  from  one  to 
the  other  is  specially  suited  to  give  rise  to  the  transfor- 
mation of  appropriate  organisms.  But  this  transforma- 
tion is  accomplished  and  established  first  in  the  new 
district  Thus  in  the  geological  series,  transitional  periods 


DEFICIENCY  OF  TRANSITIONAL  FORMS.  I49 

are  periods  of  relative  disturbance.  During  their  con- 
tinuance the  exigency  of  adaptation  and  transformation 
was  at  its  height,  both  in  the  vegetal  and  animal  world  ; 
the  conditions  of  existence  at  the  same  time  most 
unfavourable  ;  the  number  of  individuals  in  those  species 
which  succeed  in  effecting  their  transformation  is  neces- 
sarily reduced,  and  could  increase  again  only  in  the 
subsequent  periods  of  repose.  It  is  therefore  not  sur- 
prising that  the  catalogue  of  intermediate  forms  is  so 
defective ;  and  their  scarcity  is  remarked  upon  only  by 
those  who  are  determined  to  feel  the  want  of  them.  For 
the  establishment  of  scientific  evidence  in  favour  of  the 
doctrine  of  Descent  we  have  them  in  superabundance. 

With  the  supposed  deficiency  of  transitional  forms  is 
connected  another  frequent  objection,  namely,  that  in 
repeated  instances  whole  groups  of  kindred  species  have 
suddenly  appeared.  If  intermediate  morphological  and 
anatomical  gradations  are  elsewhere  visible,  in  these 
groups,  the  pterodactyls,  birds  and  others,  there  is  no 
coherence  and  connection  with  any  aboriginal  species 
previously  or  contemporaneously  existing.  This  allega- 
tion is  one  of  the  feeblest  and  most  vapid,  if  raised 
after  the  attempt  has  been  made  to  account  for  the 
absence  of  intermediate  forms.  It  is  only  a  particular 
case  in  the  alternative  that  either  all  species  originated  in 
the  natural  manner  indicated  by  the  perfectly  adequate 
number  of  transitional  forms  at  hand,  or  all  by  miracle. 
In  the  cases  which  are  here  brought  forward  as  heavy 
artillery,  the  gap  to  the  aboriginal  species  is  certainly 
greater  than  where  there  is  merely  a  leap  from  species 
to  species  or  to  genus.  But  the  explanation  given  of 
the  less  striking  intervals  scarcely  needs  extension  to 


X50  THE  DOCTRINE  OF  DESCENT. 

suffice  here  also.  The  obscurity  overshadowing  the 
extraction  of  the  birds  is  just  beginning  to  clear  up. 
Why  should  not  the  origin  of  pterodactyls  become 
more  distinct  in  the  next  few  years  ? 

A  special  difficulty  is  seemingly  prepared  for  the 
theory  by  the  highly  integrated  organs,  particularly  by 
the  apparatus  of  the  senses,  with  their  very  complex 
mechanism.  In  truth,  taking,  for  example,  the  eye  of 
the  Vertebrata,  we  need  not  even  say  of  the  higher  Ver- 
tebrata  alone  ;  its  marvellous  structure  is  well  fitted  to 
excite  the  liveliest  doubts  as  to  descent  and  selection. 
As  a  matter  of  fact,  indeed,  the  series  of  vertebrate  ani- 
mals does  not  exhibit  the  series  of  lowly  beginnings  which 
we  must  assume  as  having  once  existed.  For  the  eye  of 
the  fish  is  little  inferior  in  complexity  to  the  optic  organ  of 
the  mammal,  whilst  the  lancelet  is  completely  eyeless,  and 
therefore  affords  no  clue. 

In  other  orders  of  animals,  however,  we  still  see  in  the 
systematic  series  of  the  present  era  every  possible  gra- 
dation, and  thus  possess  a  representation  of  the  manner 
in  which  in  the  palaeontological  series  the  perfect  organ 
w^as  gradually  evolved  from  the  simplest  rudiments. 
The  lowest  crabs  present  the  simplest  mechanism 
imaginable,  sensitive  to  light ;  other  crabs  of  higher  de- 
velopment possess  eyes  somewhat  more  perfect,  not  only 
sensitive  to  light,  but  capable  of  forming  images,  and 
between  these  eyes  and  those  of  the  decapodous  crab, 
so  extremely  perfect  of  their  kind,  a  host  of  optic  struc- 
tures are  represented,  which  clearly  show  that  these 
organs  are  also  subject  to  the  law  of  slow  accumulation 
and  establishment  of  small  advantages. 

With  regard  to  the  auditory  and  olfactory  apparatus, 


CONVERGENCE.  1 5  I 

every  manual  of  comparative  anatomy  affords  testimony 
that  the  series  of  vertebrate  animals  now  living,  present 
series  of  development  which  negative  the  sudden  and 
incomprehensible  origination  of  these  organs  in  an  im- 
mediate state  of  completion.  How  they  appeared  in 
yet  lower  grades  than  are  exhibited  in  the  true  fishes 
of  the  present  time  we  may  learn  in  part  from  the 
lancelet,  and  in  part  we  may  picture  to  ourselves  from 
the  corresponding  sensory  apparatus  of  the  lower  Mol- 
lusca,  Articulata,  and  Annulosa.  With  reference  to  the 
objections  to  his  doctrine  arising  from  the  arrangements 
of  the  most  perfect  organs,  Darwin  has  said  that  he 
would  abandon  his  whole  theory  if  it  can  be  shown 
that  any  of  these  organs  could  not  possibly  have  been 
formed  from  lower  grades,  by  improvement  slowly  ac- 
quired. This  demonstration  no  one  has  yet  undertaken, 
nor  will  it  ever  be  undertaken  with  success,  as  every 
deeper  penetration  into  the  comparative  anatomy  of  the 
sensory  apparatus  affords  evidence  to  the  contrary.  In 
order  to  understand  the  presumptively  faultless  sensory 
organs  and  their  derivation  from  a  lower  grade,  it  is  of 
supreme  importance  to  bear  in  mind  the  circumstance 
first  exhibited  by  Helmholtz  in  the  eye,  that  besides  a 
number  of  perfections,  they  likewise  possess  a  number 
of  imperfections,  and  purposeless  or  obstructive  arrange- 
ments. 

But  we  must  examine  another  point,  which  may 
awaken  doubts  as  to  the  admissibility  of  the  doctrine 
of  Descent,  though,  strangely  enough,  it  has  as  yet  been 
turned  to  little  account  by  adversaries,  and  only  inci- 
dentally touched  upon  by  Darwin.  In  the  "  Origin  of 
Species,"  he  states,   that  H.   C.  Watson,  we  know  not 


152  THE  DOCTRINE  OF  DESCENT. 

where,  has  opposed  to  the  Divergence  of  Character,  oi 
the  inclination  of  varieties  and  species  to  deviate  from 
one  another,  a  Convergence  of  Character.  It  is  con- 
ceivable, he  thinks,  that  species  derived  from  different 
genera,  might  sometimes  approach  each  other  so 
closely  that  they  would  be  classed  in  the  same 
genus.  The  author  of  the  theory  of  Selection  has  beei\ 
content  to  point  out  the  great  improbability  of  such  an 
event,  which,  moreover,  in  this  simplicity  would  scarcely 
impugn  the  origin  and  truth  of  the  theory.  "If  two 
species  of  two  allied  genera  both  produced  a  number  of 
new  and  divergent  species,  I  can  believe  that  they  might 
sometimes  approach  each  other  so  closely  that  they 
would,  for  convenience'  sake,  be  classed  in  the  same  new 
genus,  and  thus  two  genera  would  converge  into  one  ; 
but  from  the  strength  of  the  principle  of  inheritance, 
and  from  the  two  parent  species  already  differing,  and 
consequently  tending  to  vary  in  a  somewhat  different 
manner,  it  seems  hardly  credible  that  the  two  new 
groups  would  not  at  least  form  different  sections  in  the 
same  genus.'"** 

We  here  see  a  theoretical  objection  theoretically 
refuted.  But  although  the  probability  of  a  convergence 
carried  to  absolute  similarity  is  extremely  slight,  and 
it  receives  no  support  from  the  palaeontological  record,  its 
utter  a  priori  impossibility  must  not  be  rashly  asserted  ; 
and  in  my  researches  on  the  Sponges  of  the  Atlantic,  I 
have  pointed  out  groups  of  species  approximating  so 
closely  as  to  be  scarcely  distinguishable.  Chalina  and 
Reniera  are  two  distinct  genera,  actually  belonging  to 
different  families.  It  is  highly  probable  that  the  genus 
Clialinula,    with     its    extremely    variable    species,    are 


CONVERGENCE.  153 

branches  of  the  ChaHna,  not  the  converse  ;  and  the  forms 
of  Reniera  Hkewise  merge  in  species  not  constant  in 
any  character,  and  which  the  most  careful  observer  is 
unable  to  distinguish  from  the  Chalinula.  Therefore,  if 
the  convergence  or  approximation  of  branches  of  various 
origin  cannot  be  rejected  in  the  abstract,  the  most  pro- 
pitious case  of  coincidence  is,  nevertheless,  limited  to 
the  province  of  analogous  formations,  where,  under  like 
conditions  of  adaptation,  different  famihes  have  been 
driven  to  like  expedients  and  differentiations,  producing 
complete  similarity.  A  general  survey  of  the  organic 
world  likewise  teaches  us  that  in  the  higher  regions  this 
overlapping  of  the  ends  of  dissimilar  parentage  becomes 
more  and  more  incredible,  and,  as  is  shown  by  my  study 
on  sponges,  they  can,  in  any  case,  occur  only  where  the 
organisms  consist  of  very  simple  factors,  highly  variable 
in  a  few  directions,  and  very  easily  affected  by  external 
conditions. 

When  we  referred  above  to  the  possibility  of  no 
slight  objection  to  the  doctrine  of  Descent,  we  spoke 
of  another  case  of  convergence.  We  mean,  namely, 
those  similar  final  results  in  divergent  series  by  which, 
in  highly  organized  groups  of  animals,  of  which  the 
reciprocal  connection  can  be  traced  only  through  low 
aboriginal  forms,  certain  important  organs  exhibit  the 
greatest  uniformity  of  arrangement  and  integration. 
It  is,  as  yet,  quite  undecided  where  and  when  the  true 
insects  separated  themselves  from  the  water-breathing 
crabs  ;  nay,  some  naturalists  incline  to  the  opinion  that 
these  two  classes  are  derived  from  a  more  remote 
common  ancestor.  Thus  much  is  extremely  probable, 
tliat  the  severance  between  crabf;  and  insects  took  place 


154  THE  DOCTRINE   OF   DESCENT. 

when  the  development  of  their  optic  apparatus  had  not 
attained  the  degree  of  perfection  which  we  now  find  in 
the  stalk-eyed  crabs  and  insects.  They  nevertheless 
agree  not  merely  in  their  coarser  conditions,  but,  as 
Max  Schultze  has  demonstrated,  even  in  their  minutest 
microscopic  details.  If  the  idea  of  design  as  a  principle 
of  explanation  is  excluded  in  this  case  also,  as  will  be 
shown  below,  and  as  is  self-evident  from  our  standpoint, 
and  if  simple  heredity  in  the  two  series  must  be  excluded 
likewise,  some  other  adequate  solution  must  be  sought. 

The  case  of  the  converging  species  of  sponges  may 
throw  a  light,  feeble  though  it  be,  upon  the  obscure  pro- 
cesses of  the  organic  laboratory.  Let  us  here  again 
recall  that  maxim  of  Goethe,  which  we  have  already 
cited :  "  The  animal  is  formed  by  circumstances  for 
circumstances."  Perhaps  this  maxim  may  in  future  be 
brought  into  play,  for  it  is  actually  a  question  of  in- 
vestigating how  surrounding  conditions,  the  agencies 
acting  on  the  sensory  apparatus,  can  exercise  on  simple 
matter  such  an  influence,  that  the  otherwise  widely 
differing  descendants  of  the  various  possessors  of  this 
simple  material  or  incomplete  organs,  have  acquired  a 
more  complete  organ,  not  only  working  in  a  similar 
manner,  but  of  similar  construction.  Darwinism  has 
never  yet  pretended  to  have  explained  everything ; 
neither  will  it  be  wrecked  on  this  point,  but,  on  the  con- 
trary, will  only  have  supplied  fresh  incitements  to  more 
profound  researches,  crowned  by  beautiful  results. 

Another  example  of  approximation  in  divergent 
series  is  afforded  by  the  eyes  of  the  highest  molluscs, 
the  Cephalopods,  as  compared  with  those  of  the  Ver- 
tebrata  ;    in    this    instance,   however,    it   does   not    go 


SYSTEMATIC  SCHOOL.  I55 

beyond  an  analogy,  though  a  striking  one.  It  is  only 
the  microscopic  structure  of  the  nerve  membrane, 
which  is  extremely  similar  in  both  divisions,  with  the 
exception  of  the  reversed  sequence  of  the  layers 
from  inwards,  outwards.  The  case,  considered  in  the 
abstract,  appears  highly  complicated,  and  without  a 
prospect  of  solution;  but  it  becomes  marvellously 
simplified,  as  we  have  already  hinted,  if  the  question 
is  thus  generalized  :  In  what  manner  are  the  still  un- 
differentiated terminations  of  the  nerves  affected  by  the 
specific  operation  of  the  waves  of  light  and  sound,  &c., 
so  as  to  assume  the  form  and  construction  of  specific 
peripheral  organs  ?  It  may  be  long  before  these  relations 
are  fathomed  ;  our  only  concern  is  to  defend  the  theory 
from  the  reproach  of  inadequacy,  by  showing  the  scope 
for  investigation  according  to  our  point  of  view. 

When  Darwin  had  brought  to  light  the  effects  of  natu- 
ral selection  in  reproduction  and  derivation,  and  applied 
this  principle  to  all  the  phenomena  of  the  organic 
world,  the  Doctrine  of  Descent,  thus  fortified  and  estab- 
lished, practically  subdued  the  systematic  school  which 
Lamarck  had  vainly  resisted,  to  the  theory  of  transmuta- 
tion. The  systematic  school  classified  organisms  ac- 
cording to  external  and  internal  resemblances.  Whence 
this  greater  or  smaller  accordance,  whence  the  grada- 
tion and  the  heterogeneity,  it  knew  not  how  to  tell. 
It  was  thought  that  much  was  gained  when  the  funda- 
mental forms  of  types  were  spoken  of,  even  though 
no  account  was  given  of  the  intrinsic  nature  of  these 
types,  floating  like  ideas  above  the  phenomena.  Now 
the  type  has  become  the  family,  and  the  systematizers 
have    the    plain    task    of    restoring    and    combining    the 


I  $6,  THE  DOCTRINE  OF  DESCENT. 

pedigrees  of  the  various  groups  of  living  beings.  The 
knowledge  of  these  pedigrees  has  now  for  the  first  time 
a  truly  scientific  purport,  as  compared  with  the  old 
system  of  types;  for  the  genealogical  trees  cannot  be 
constructed  without  a  knowledge  of  their  growth,  and 
of  the  causes  which  produced  their  branches,  twigs,  and 
shoots.  Each  family  thus  includes  all  the  forms  derived 
from  one  simple  original  form.  The  old  systematic 
school  was  obliged  to  content  itself  with  working  out 
the  classification  of  the  individual  types,  and  defining 
their  limits,  and  then  balancing  the  types  against  each 
other  on  general  morphological  and  physiological 
principles,  in  order  to  estimate  their  relative  value,  all 
without  any  consciousness  of  the  natural  causes  of  these 
actual  relations.  The  doctrine  of  Descent  connects  the 
original  forms  of  the  types  afresh  from  the  point  of 
view  of  consanguinity,  and  descends  deeper  and  deeper, 
down  to  the  simplest  organisms,  and  the  beginning  of 
life. 

But  before  we  attempt  to  come  to  an  understanding 
as  to  the  origin  of  life,  one  of  the  pillars  of  the  doctrine 
of  Descent,  it  seems  appropriate  to  allude  to  the  question 
whether  natural  selection,  of  which  the  means  and  effects 
will  bemore  minutely  elucidated  in  the  following  chapters, 
is  capable  of  explaining  all  the  modifications  of  organic 
beings,  and  whether  selection  must  always  be  summoned 
to  aid  in  the  explanation  of  these  transformations  .?  In 
other  words,  whether  the  theory  of  selection  answers  all 
the  requirements  of  the  doctrine  of  Descent,  or  whether 
it  is  capable  and  in  need  of  amendment  ?  We  may  do 
this  with  the  more  impartiality,  as  the  acute  author  of 
the  book  entitled  "  The  Unconscious  from  the  Stand- 


IS  THE  THEORY  OF  SELECTION  SUFFICIENT?    1 57 

point  of  Physiology  and  the  Theory  of  Descent  (Das 
Unbewusste  vom  Standpunkt  der  Physiologic  and  Des- 
cendenztheorie)/®  has  again  recently  observed  that  the 
truth  of  the  doctrine  of  Descent  is  independent  of  the 
bearings  and  adequacy  of  the  Darwinian  theory. 

"  This  circumstance,"  he  says,  "  is  misunderstood  by 
the  majority  of  Darwin's  opponents  ;  when  they  adduce 
arguments  for  the  inadequacy  of  natural  selection  in 
the  struggle  for  life,  they  usually  fancy  they  have 
adduced  just  as  many  arguments  against  the  reliability 
of  the  theory  of  Descent.  But  the  two  have  no  direct 
connection  with  one  another ;  for  it  might  be  possible 
that  Darwin's  theory  of  natural  selection  was  absolutely 
false  and  unserviceable,  and  the  doctrine  of  derivation 
true  notwithstanding ;  that  only  the  causal  medium  of 
the  derivation  of  one  species  from  another  w^as  different 
from  that  stated  by  Darwin.  Similarly,  it  might  be 
possible  that,  although  the  mediate  causes  of  transition 
discovered  by  Darwin  were  partially  effective, — on  the 
other  hand,  transitional  phenomena  existed  which  could 
not  as  yet  be  explained  by  this  hypothesis  ;  that  this 
therefore  required  either  an  auxiliary  hypothesis  supple- 
menting that  of  Darwin,  or  even  a  co-ordinating  prin- 
ciple of  explanation,  as  little  discovered  now  as  was  the 
Darwinian  theory  twenty  years  ago.  Such  imperfect 
knowledge  of  the  causes  operating  in  the  transition  of 
one  form  into  the  other,  can  prejudice  the  general 
truth  of  the  doctrine  of  Descent  as  little  as  the  absence 
of  intermediate  forms,  or  the  uncertainty,  still  exist- 
ing in  many  cases,  of  the  derivation  of  any  given  form. 
If  even  in  former  times,  when  all  knowledge  of  the 
causes  by  which  transition  is  effected  was  still  wanting, 


(58  THE  DOCTRINE  OF   DESCENT. 

the  doctrine  of  Derivation  seemed  certain  to  the  greatest 
minds,  on  philosophical  and  d  priori  grounds,  there  can 
be  still  less  doubt  as  to  the  theory  of  Descent,  now 
that  Darwin  and  Wallace  have  plainly  shown  that  in- 
dubitably the  most  important,  if  not  the  all-sufficing 
cause  of  transition  is  everywhere  effective,  and  in  many 
cases  sufficient." 

We  wished  to  set  forth  these  words  of  a  talented  philo- 
sopher for  the  benefit  of  those  who  are  so  unreasoning  as 
to  pour  away  the  child  with  the  bath-water,  and  fancy 
that  they  have  slain  the  doctrine  of  Descent  when  they 
have  been  lucky  enough  to  raise  a  few  cavils  against 
Darwin's  theory  of  selection.  Does  the  theory  of  selec- 
tion fulfil  every  requirement.'^  It  accomplishes  many 
and  great  things,  but  in  some  cases  it  seems  to  be  in- 
adequate, and  in  other  cases  it  is  not  requisite,  as  the 
solution  of  the  formation  of  species  is  found  in  other 
natural  conditions. 

Moritz  Wagner,  a  decided  adherent  of  Metamorphosis 
and  an  enthusiastic  admirer  of  Darwin,  endeavoured  to 
establish  a  "  law  of  migration,"  namely,  that  "  the  migra- 
tion of  organisms  and  the  formation  of  colonies  by  them 
is  the  necessary  condition  of  natural  selection."'''  In 
his  opinion,  new  species  arise  only  when  smaller  com- 
munities of  individuals,  in  process  of  forming  varieties, 
are  geographically  isolated,  as  in  this  manner  only  is 
intercrossing  precluded  with  their  stationary  congeners, 
who  do  not  participate  in  the  transformation  ;  and  rever- 
sion and  disappearance  of  characters  as  yet  not  fixed 
is  thus  avoided.  That  isolation  often  acts  very  favour- 
ably on  the  formation  of  species  is  a  fact  almost  univer- 
sally acknowledged  and  easily  verified  by  insular  fauna, 


LAW   OF   MIGRATION.  1 59 

but  that  the  formation  of  species  can  take  place  only 
with  the  assistance  of  isolation  has  been  effectively 
refuted  by  Weismann.^^  He  has  shown  that  an  "  inter- 
crossing of  the  incipient  variety  with  the  aboriginal  form 
is  not  avoided  by  isolation  ;  "  through  the  instance 
derived  from  the  Steinheim  lake,  of  the  formation  of  a 
new  species  amid  the  older  formations.  On  Haeckel's 
remark  that  in  the  asexual  propagation  of  the  lower 
beings,  the  influence  of  intercrossing  was  not  to  be 
feared,  Wagner  had  already  restricted  the  necessity  of 
isolation  to  the  higher  organisms  with  separate  sexes. 
But  Weismann  most  justly  insists  that  Wag^iier's  "  law 
of  migration  "  is  deprived  of  all  foundation  by  one  of 
the  most  remarkable  examples  of  the  formation  of 
varieties  on  the  same  territory,  namely,  the  fact  of  the 
separation  of  the  sexes,  as  to  the  derivation  of  which 
from  species  once  hermaphrodite,  all  (the  believers 
in  Creation  naturally  excepted)  are  assuredly  of  one 
accord. 

As  we  have  already  mentioned,  it  seems  as  if  the 
impulse  to  form  varieties  once  exists,  the  tendency 
spreads  rapidly.  Proof  of  such  periods  of  variation 
is  to  be  found  in  the  Palaeontological  investigations 
on  page  96.  If  isolation  coincides  with  such  a  period, 
it  effects  the  establishment  of  new  varieties  into 
species  without  the  aid  of  natural  selection.  As 
Darwin  admits  in  his  work  on  the  origin  of  Man,  he 
formerly  bestowed  too  little  attention  on*  the  forma- 
tion of  so-called  morphological  species.  By  this  we 
mean,  species  not  distinguished  from  their  aboriginal 
stocks  by  any  physiological  advantages,  and  hence  not 
superior   to   them,    in   which    therefore    the    principle   of 


l60  THE  DOCTRINE   OF   DESCENT. 

selection  in  the  strict  Darwinian  sense  is  inapplicable. 
Two  species  of  butterflies,  differing  only  in  a  few  specks 
or  pencilings,  or  the  notches  on  the  wings,  are  in 
our  estimation  of  perfectly  equal  physiological  value ; 
they  are  morphological  species.  Weismann  sets  up 
the  proposition  that  "  the  colouring  and  penciling  of 
the  upper  surface  of  the  wing  in  butterflies  are  to  be 
regarded  as  purely  morphological  characters,  excepting 
in  cases  of  mimicry  and  protective  uniform  colouring." 
He  shows  also  by  other  examples  that,  "  under  certain 
circumstances  and  within  a  comparatively  small  range, 
new  as  well  as  morphological  characters  may  be  estab- 
lished by  the  effects  of  isolation  only."  The  inapplica- 
bility of  natural  selection  to  the  evolution  of  purely 
morphological  variations  was  first  pointed  out  by 
Nageli.*^  With  reference  to  this  subject,  Darwin  with 
magnanimous  modesty  observes :  "  I  now  admit,  after 
reading  the  essay  by  Nageli  on  plants,  and  the  remarks 
by  various  authors  with  respect  to  animals,  more  espe- 
cially those  recently  made  by  Professor  Broca,^"  that,  in 
the  earlier  editions  of  my  'Origin  of  Species,'  I  probably 
attributed  too  much  to  the  action  of  natural  selection 
or  the  survival  of  the  fittest.  I  have  altered  the  fifth 
edition  of  the  *  Origin  '  so  as  to  confine  my  remarks 
to  adaptive  changes  of  structure.  I  had  not  formerly 
sufficiently  considered  the  existence  of  many  structures, 
which  appear  to  be,  as  far  as  we  can  judge,  neither  bene- 
ficial nor  injurious,  and  this  I  believe  to  be  one  of  the 
greatest  oversights  as  yet  detected  in  my  work."  *^ 

We  are  disposed  to  think  that  the  oversight  with 
which  Darwin  charges  himself  is  not  so  great,  as  it  is 
here  a  question  of  the  more  indiflerent  species,  not  affect- 


ORIGIN  OF  LIFE.  l6l 

ing  the  great  phenomena  of  progressive  development, 
and  of  which  the  origin  is  perfectly  comprehensible  by 
variability  alone,  or  in  any  case,  as  we  have  seen,  by 
variability  with  the  co-operation  of  isolation.  The  value 
of  natural  selection  is  in  no  way  deteriorated  by  the 
possibility  of  explaining  the  purely  morphological 
species  without  its  aid.  In  certain  cases  of  mimicry, 
or  the  formation  of  natural  protective  masks  and  imi- 
tations, and  for  the  explanation  of  organic  beauty, 
natural  selection  seems  inadequate.  But  what  does  this 
prove,  but  that,  as  all  know,  future  generations  must 
needs  carry  on  the  edifice  ?  The  additions  contributed  by 
the  Present  to  the  theory  of  selection  are  scarcely  worthy 
of  mention. 

As  the  type  has  become  the  family,  and  the  system, 
as  the  shortest  expression  of  tJie  kindred  relations  of 
organisms,  requires  at  the  root  of  the  genealogical  tree 
a  number  of  the  lowest  and  simplest  organisms,  or  per- 
haps one  single  primordial  form,  Ave  must  come  to  an 
understanding  as  to  the  problem  of  the  beginning  of  hfe. 
Even  quite  recently,  in  March  1873,  Max  Miiller,  in 
accordance  with  an  opinion  shared  by  many,  has  again 
proclaimed  **  tlie  Darwinian  theory  vulnerable  at  the 
beginning  and  at  the  end."*'*  Whether  any  considerable 
points  of  attack  are  offered  by  the  final  proposition  of 
Darwinism,  namely,  the  application  of  natural  selection 
to  man,  and  his  sole  characteristic  peculiarity,  language, 
we  shall  have  another  opportunity  of  inquiring.  But 
•what  the  renowned  linguist  terms  the  vulnerable  begin- 
ning of  Darwinism,  the  origin  of  life,  has  in  fact  nothing 
to  do  with  actual  Darwinism,  or  natural  selection,  unless 
the  principle  of  selection  be  extended  to  the  inorganic 


l62  THE  DOCTRINE  OF  DESCENT. 

world  of  matter.  But  the  objection  which  endeavours 
to  cut  aivay  the  ground  from  under  the  doctrine  of 
Descent,  not  the  theory  of  selection,  and  represents  the 
origin  of  life  as  incomprehensible  and  supernatural,  we 
naturally  regard  as  an  attempt  to  gain  a  precedent  for 
the  supernatural  creation  of  language.  Between  begin- 
ning and  end,  we  naturalists  may  do  as  we  please. 

E»at  it  is  strange  that  the  very  side  which  is  so  ready 
to  reproach  us  with  a  want  of  pliilosophic  method  and 
induction,  should  here,  where  the  material  substratum 
is  deficient,  dispute  the  claims  of  the  investigation  of 
nature  to  its  logical  inferences.  In  the  last  page  of 
the  "  Origin  of  Species,"  Darwin  says :  "  There  is 
grandeur  in  this  view  of  life,  with  its  several  powers, 
having  been  originally  breathed  by  the  Creator  into 
a  few  forms  or  into  one  ;  and  that,  whilst  this  planet 
has  gone  cycling  on  according  to  the  fixed  law  of 
gravity,  from  so  simple  a  beginning  endless  forms 
most  beautiful  and  most  wOnderful  have  been  and 
are  being  evolved."  In  this  concession,  Darwin  has 
certainly  been  untrue  to  himself;  and  it  satisfies  neither 
those  who  believe  in  the  continuous  work  of  creation 
by  a  personal  God,  nor  the  partizans  of  natural  evolution. 
It  is  directly  incompatible  with  the  doctrine  of  Descent, 
or,  as  Zollner "  says  :  "  The  hypothesis  of  an  act  of 
creation  (for  the  beginning  of  life)  would  not  be  a  logi- 
cal but  a  merely  arbitrary  limitation  of  the  causal  series, 
against  which  our  intellect  rebels  by  reason  of  its  inherent 
craving  for  causality."  Whoever  does  not  share  this  crav- 
ing is  beyond  help,  and  he  cannot  be  convinced.  To 
hold  the  beginning  of  life  as  an  arbitrary  act  of  creation, 
is  to  break  with  the  whole  theory  of  cognition. 


BEGINNING  OF   LIFE.  1 63 

The  verdict,  as  to  the  beginning  of  Hfe,  is  commonly 
dependent  on  the  standpoint  adopted  with  respect  to 
the  possibility  of  primordial  or  spontaneous  generation 
(generatio  equivoca).  This  course  is,  in  our  opinion, 
only  half  correct.  The  subtlest  experiments  on  spon- 
taneous generation,  whether  from  organic  matter  or 
from  constituents  not  yet  combined  into  molecules  of 
organic  matter,  have  proved  indecisive  on  both  sides. 
Neither  the  impossibility  nor  the  possibility  can  be  ex- 
perimentally demonstrated  ;  it  always  remains  open  to 
the  sceptic  to  say,  if  nothing  appears,  that  the  failure  of 
spontaneous  generation  is  due  to  the  conditions  of  the 
experiment ;  or  if  anything  does  make  its  appearance, 
that,  notwithstanding  every  precaution,  germs  made 
their  way  into  the  infusion.  Opinion  as  to  continued 
primordial  genesis  still  taking  place,  is  thus  a  mere 
emanation  of  the  general  theory  of  nature  held  by  each 
individual.  To  any  one  who  holds  open  the  possibility 
that,  even  now,  animate  may  be  evolved  from  inanimate 
existence,  without  the  mediation  of  progenitors,  the  first 
origin  of  life  in  this  natural  method  is  at  once  self-evident. 
But  even  if  the  proof  were  given,  which  never  can  be 
given,  that  in  the  present  world  spontaneous  generation 
does  not  occur,  the  inference  would  be  false  that  it  never 
did  occur.  When  our  planet  had  reached  the  phase 
of  development  in  which  the  temperature  of  the  surface 
admitted  of  the  formation  of  water  and  the  existence 
of  albuminous  substances,  the  quantitative  and  qualita- 
tive conditions  of  the  atmosphere  were  different  from 
what  they  now  are.  A  thousand  circumstances  now 
be^'^ond  our  control,  and  as  to  the  possible  nature  of 
which  it  is  needless  to  speculate,  might  lead  to  the  pro 


1 64  THE  DOCTRINE  OF  DESCENT. 

duction  of  protoplasm,  that  primordial  organism,  from 
the  atoms  of  its  constituents. 

Hence  the  beginning  of  life  at  some  bygone  period 
is  likewise  not  susceptible  of  demonstration  ;  but  the 
commencement  of  animate  being  at  some  definite  era 
of  development  is  a  logical  necessity,  and  by  no  means 
a  vulnerable  point  in  the  doctrine  of  Descent.** 

We  have  already  incidentally  mentioned  a  man  who, 
although  not  so  eminent  as  Darwin,  has  the  glory  of 
having  independently  discovered  the  law  of  natural 
selection,  and  of  having,  after  Darwin  had  come  forward 
with  his  fundamental  work,  supported  the  theory  of 
selection  by  a  profusion  of  original  observations.  This  is 
Alfred  Russell  Wallace."  In  a  paper,  published  in  1855, 
he  demonstrated  the  dependence  of  the  flora  and  fauna 
on  the  geographical  position  and  geological  nature  of 
the  district  of  propagation,  and  the  close  connection  of 
the  species,  according  to  time  and  habitat,  with  kindred 
species  previously  existing ;  and  in  a  second  work,  in 
the  year  1858,  on  the  inclination  of  varieties  to  deviate 
without  limit  from  the  original  type,  we  find  a  dis- 
quisition on  the  importance  of  the  struggle  for  exist- 
ence, the  consequences  of  adaptation,  the  selection  of 
the  most  useful,  and  the  replacement  of  the  earlier 
species  by  the  establishment  of  the  more  valuable 
varieties.  We  shall  repeatedly  have  occasion  to  draw 
upon  the  rich  supplies  of  his  researches. 


VIII. 

ITeredity  —Reversion — ^Variability— Adaptation — Results  of  Use  and  Disiise  of 
Organs — Differentiation  leading  to  Perfection. 

The  two  properties  of  organic  being  which  determine 
and  regulate  the  relation  of  the  offspring  to  the  pro- 
genitors, and  which  not  only  assign  to  individuals  theii 
position  in  the  surrounding  world,  but  also  help  them  to 
attain  it,  are  transmission  or  heredity,  and  adaptation. 

Heredity  is  the  conservative,  adaptation,  the  pro- 
gressive principle.  Yet  all  heredity  is  not  directed  to 
immutability,  and  many  cases  of  adaptation  involve 
morphological  and  physiological  retrogression.  For  the 
elucidation  of  the  inherited  peculiarities  of  organisms,  we 
reconstruct  their  pedigree  ;  by  the  characters  acquired  by 
adaptation,  we  test  the  pliability  of  organisms  in  the 
lapse  of  time,  and  trace  the  ramifications  of  the  pedigree. 
Groups  of  organisms,  in  w^hich  the  conservative  principle 
predominates,  certainly  evince  their  powers  of  endurance 
in  the  struggle  for  existence,  but  they  make  no  advance 
in  physiological  value,  and  are  outstripped  by  the  more 
progressive  groups  which  yield  to  obstacles  and  profit  by 
them,  a  course  of  which  human  life  also  affords  so  many 
examples. 

As  the  phenomena  of  heredity  are  usually  more  obvious 
than  the  results  of  adaptation,  the  latter  was  almost 


l66  THE  DOCTRINE  OF   DESCENT. 

entirely  neglected  by  naturalists  in  former  days.  And 
indeed  what  comparison  in  organic  nature  can  be  made 
so  frequently  and  universally  as  the  resemblance  of 
the  offspring  to  the  parent  ?  An  anatomist,  it  is  true, 
quaintly  attempted  to  work  out  the  proposition  that  the 
resemblance  in  the  children  is  not  dependent  on  heredity, 
but  is  the  result  of  identical  and  similar  influences,  cus- 
toms, and  habits,  prevalent  in  families.  But  this  para- 
doxical theory  requires  no  special  refutation.  It  is 
quite  true  that  similar  habits  and  similar  external  im- 
pulses elicit  a  certain  similarity  of  demeanour  and 
appearance ;  but  if  the  little  son  of  the  pompous  mil- 
lionaire apes  his  father,  it  cannot  be  said  that  he  has 
likewise  mimicked  his  large  or  small  nose,  &c.,  or  has 
acquired  it  by  a  similar  call  for  adaptation.  We  have 
only  cursorily  alluded  to  this  quibble,  in  flagrant  contra- 
diction as  it  is  with  every  experience;  and,  in  conformity 
with  general  opinion,  we  corroborate  the  transmission  of 
the  parental  characteristics  to  the  offspring.  The  breeders 
of  animals  in  particular  has  occasion  to  observe  these 
transmissions  specially,  and  to  evolve  their  astounding 
progress  from  the  combination  and  reciprocal  influence 
of  the  various  forms  and  degrees  of  heredity. 

It  is  well  known  that  not  only  are  normal  conditions 
transmitted,  but  monstrosities  are  also  reproduced  through 
several  generations,  and,  as  we  have  seen  in  the  instance 
of  the  crook-legged  sheep  of  Massachusetts,  may  even  be 
established  as  the  characters  of  a  race.  A  mere  reference 
to  the  inheritability  of  morbid  tendencies,  bodily  and 
mental,  will  enable  us  to  realize  this  intrinsic  connection 
of  the  offspring  to  the  ancestors.  Only  since  the  theory 
of  selection  has  rendered  the  modalities  of  the  transmis- 


HEREDITY.  I67 

sion  of  bodily  characters  a  subject  of  more  profound 
study,  have  general  and  national  psychology  been  im- 
pelled to  estimate  the  influence  of  heredity  in  the  province 
of  the  mind,  and  demonstrate  how,  in  the  various  races 
and  families  of  nations,  the  molecular  peculiarities  of  the 
brain,  the  tendency  of  character  and  intelligence  of  the 
individuals,  and  whole  series  of  ideas,  conform  both  in 
vigour  and  purport  to  the  laws  of  heredity. 

It  is  manifest  that  the  key  to  the  phenomena  of  he- 
redity must  be  looked  for  in  the  process  of  reproduction. 
The  molecular  motions  and  disturbances,  the  incon- 
ceivably minute  mechanical  transfers  which  take  place, 
do  not,  indeed,  admit  of  observation.  They  are,  however, 
no  more  "  obscure "  and  "  enigmatical,"  as  they  are  so 
readily  termed,  than  the  invisible,  but  not  supernatural 
motions,  on  the  control  and  calculation  of  which  the 
stately  edifice  of  theoretic  Chemistry  and  Physics  se- 
curely rests.  With  the  advance  from  asexual  to  sexual 
reproduction,  and  from  the  simple  to  the  more  perfect 
organisms,  the  difficulty  of  representation  increases,  but 
not  that  of  abstract  comprehension.  If  a  low  organism, 
a  monad,  divides  itself,  the  divided  individuals  differ  from 
the  parent  individual  only  in  their  inferior  bulk,  and  the 
difference  of  their  functions  is,  as  to  quality,  nil. 

So,  too,  where  gemmules  and  germs  separate  from  a 
parent  organism,  the  dower  of  the  oflspring  is  so  large 
that  identity  in  form  and  function  of  progenitor  and 
progeny  appears  self-evident  and  natural.  But  the  sexual 
reproduction  of  composite  organisms  is,  as  we  have 
known  since  the  old  doctrine  of  the  aura  seminalis  was 
refuted,  also  a  separation  of  material  portions  of  the  pa- 
rental organisms.     It  is  still  a  mechanical  process  which 


1 58  THE  DOCTRINE  OF   DESCENT. 

Is  not  incomprehensible,  and  seems  inexplicable  only  if 
we  make  the  naturally  futile  attempt  to  bring  sensibly 
before  us  the  infinitely  minute  agencies  which  operate 
both  mechanically  and  chemically.  In  the  "  Variation  of 
Plants  and  Animals,"  Darwin  has  set  up  a  provisional 
hypothesis  of  Pangenesis.  He  says  that  all  phenomena 
of  heredity  and  reversion  would  thereby  be  rendered 
possible,  til  at  in  every  elementary  or  cellular  portion  of 
the  organism  innumerable  gemmules  are  produced,  which 
are  hoarded  up  in  the  reproductive  elements,  in  every 
ovum,  in  every  sperm  corpuscule,  and  might  remain 
latent  during  hundreds  of  generations,  and  only  then 
exhibit  their  powers  in  reversion.*®  This  hypothesis,  it 
appears,  has  met  with  no  ready  approbation,  probably, 
as  it  seems  to  us,  because,  in  the  attempt  to  meditate 
upon  it,  the  sensible  representation  forces  itself  forward 
only  to  prove  inadequate.  But  if  it  be  steadfastly  borne 
in  mind  that  in  Protoplasm,  as  Rollet "  appropriately 
terms  it,  the  most  complex  phenomenal  forms  of  life 
possess  a  most  persistent  witness  of  their  connection 
with  the  simplest,  it  follows  that  the  general  laws 
shown  to  be  true  or  probable  with  reference  to  the 
simplest  organisms,  must  be  applicable  to  the  most 
perfect  also.  This  holds  good  also  in  reproduction, 
which,  in  its  fundamental  phenomena,  offers  nothing 
that  cannot  be  based  upon  molecular  physics  applied 
to  colloidal  living  substance  capable  of  imbibition,  and 
thus  divested  of  vitalistic  dualism. 

The  more  highly  complex  is  an  organism,  that  is,  the 
greater  the  differentiation  in  the  development  from  the 
protoplasm  of  the  germ-cell  to  maturity,  the  more 
heterogeneously   does  heredity   display   itself.      These 


REVERSION.  169 

modes  of  heredity  have  been  defined  by  Darwin, 
and  yet  more  systematically  by  Haeckel,  as  "laws  of 
inheritance,"  and  corroborated  by  them  by  a  profu- 
sion of  examples.  If  heredity  may  be  termed  the 
conser\^ative  element  in  the  life  of  species,  we  may  also 
speak  in  particular  of  a  conservative  heredity,  by 
which  the  old,  long-established  characteristics  and  pe- 
culiarities are  transferred.  The  more  stubbornly  a 
character  is  transmitted,  or,  what  amounts  to  the  same, 
the  greater  the  number  of  families,  genera,  and  species, 
over  which  a  character  is  extended,  the  more  ancient 
must  it  be  considered,  the  earlier  did  it  appear  in  the 
ancestral  stock.  In  most  cases,  this  consei-vative  he- 
redity occurs  in  an  unbroken  succession  of  generations, 
an  observation  on  which  it  is  needless  to  enlarge, 
as  it  may  be  daily  made  by  every  one.  But  con- 
servative heredity  may  likewise  display  itself  inter- 
mittently, either  when  merely  individual  characters  of 
the  ancestors  reappear  after  lying  dormant  for  one, 
several,  or  many  generations, — a  phenomenon  desig- 
nated as  Atavism,  or  reversion, — or  when  the  species 
is  composed  of  a  regular  alternation  of  variously  con- 
stituted generations  and  individuals.  This  particular 
sort  of  reversion  is  termed  Alternate  Generation,  or 
Hcterogenesis. 

No  one  is  surprised  if  children  exhibit  the  bodily 
or  mental  features  of  their  grand-parents  which  were 
suspended  in  the  parents.  But  most  frequent  and 
striking  is  the  atavism  of  domestic  animals  and  culti- 
vated plants,  a  stubborn  antagonist  to  breeders.  Of  no 
domestic  animal  is  the  aboriginal  stock  known  with  such 
approximate  certainty  as  that  of  the  pigeon.    Now  there 


I/O  THE   DOCTRINE   OF  DESCENT. 

are  races  of  pigeons  purely  bred  for  several  centuries, 
and  in  colour  and  shape  transformed  into  new  creatures, 
which  yet  from  time  to  time  spontaneously,  or  by 
crossing  with  other  conspicuous  races,  produce  birds 
which,  in  colouring  and  characteristic  pencilings  of 
black  bars  on  wings  and  tail,  resemble  the  wild  rock- 
pigeon. 

"I  paired,"  says  Darwin,**  "a  mongrel  female 
barb-fantail  with  a  mongrel  male  barb-spot,  neither 
of  which  mongrels  had  the  least  blue  about  them. 
Let  it  be  remembered  that  blue  barbs  are  excessively 
rare ;  that  spots,  as  has  been  already  stated,  were 
perfectly  characterized  in  the  year  1676,  and  breed 
perfectly  true ;  this  likewise  is  the  case  with  white 
fantails,  so  much  so  that  I  have  never  heard  of  white 
fantails  showing  any  other  colour.  Nevertheless,  the 
offspring  from  the  above  two  mongrels  was  of  exactly 
the  same  blue  tint  over  the  whole  back  and  wings  as 
that  of  the  wild  rock-pigeon  of  the  Shetland  Islands  ; 
the  double  black  wing-bars  were  equally  conspicuous  ; 
the  tail  was  exactly  alike  in  all  its  characters,  and  the 
croup  was  pure  white." 

Another  reversion  frequently  to  be  observed  is  the 
striping  of  the  feral  domestic  cat  of  Europe,  in  which 
it  resembles  the  wild-cat  so  closely  as  to  be  scarcely 
distinguishable.  Darwin  has  collected  evidence  from 
which  we  may  infer  that  the  wald  ancestral  stock  of 
the  horse  was  striped,  and  this  evidence  includes  the 
appearance  of  striped  individuals.  But  yet  another 
strange  phenomenon  in  horses  may  be  interpreted  by 
atavism.  Foals  are  occasionally  born  with  supernumerary 
toes.     This  "  monstrosity "  can   be  explained    only  by 


PROGRESSIVE  HEREDITY.  I71 

reversion  to  the  three-toed  historical  ancestors  of  the 
present  genus.     These  vouchers  are  sufficient. 

All  the  phenomena  of  artificial  breeding,  as  well  as 
natural  selection,  serve  to  show  that  not  only  the  cha- 
racters descended  from  past  ages,  but  also  those  subse- 
quently and  most  recently  acquired,  may  be  transmitted 
to  posterity.  This  is  progressive  heredity.  Without 
it,  improvement  and  progress  would  be  impossible  ;  and 
its  own  possibility  is  the  direct  result  of  the  nature  of 
reproduction.  The  newer  a  useful  modification,  the  less 
has  it  hitherto  been  able  to  place  itself  in  correlation 
with  the  entire  organism,  the  less  is  the  reproductive 
system  as  yet  affected  by  it ;  the  more  uncertain  and 
fluctuating,  therefore,  is  the  transfer  by  propagation  ; 
breeding,  or  natural  selection,  is  requisite  to  convert  the 
potentiality  of  progress  into  a  fact,  and  gradually  to 
enrol  this  fact  among  the  conservative  inheritances. 

Progressive  heredity  is  naturally  more  complex  where 
the  sexes  are  separate,  where  sexual  selection  asserts 
its  rights,  and  the  advantages  of  one  sex  are  fostered 
by  the  taste  of  the  other,  and  are  then  either  trans- 
ferred exclusively  to  the  sex  benefited  by  its  secondary 
characters,  or  turned  to  the  profit  of  the  whole  species. 
As  a  rule,  the  males  are  endowed  with  these  advantages, 
and  have  transmitted  them  incompletely  to  the  females. 
We  will  explain  ourselves  by  a  single  example.  In  the 
order  of  insects  termed  Orthoptera  (or  straight-winged), 
the  males,  by  rubbing  their  wing-covers  together,  or  by 
stroking  them  with  the  lower  portion  of  their  hind  legs, 
are  able  to  make  a  music  attractive  to  the  females. 
Von  Graber,  a  distinguished  modern  entomologist,  has 
shown"  that  the  teeth  of  the  stridulating  instruments  of 


172  THE  DOCTRINE  OF  DESCENT. 

these  animals  are  merely  modified  hairs  ;  that  their  con< 
struction  may  be  explained  by  their  use  ;  and  that  in  all 
probability  they  have  been  perfected  by  sexual  selec- 
tion, the  best  and  loudest  musicians  being  the  most 
favoured  wooers.  With  one  single  exception,  the  females 
of  the  Orthoptera  are  dumb,  but  many  possess  traces  or 
the  stridulating  apparatus  peculiar  to  the  males.  Con- 
trary to  the  older  opinion,  that  it  was  merely  a  case 
of  transmission  emanating  from  the  males,  Graber  has 
made  it  "more  than  probable  that  the  resonant  ner- 
vures  of  the  females — of  the  stridulating  Ephippigera 
vitium — have  been  gradually  developed  independently 
of  the  males,  but  in  the  same  manner."  In  other  cases, 
on  the  contrary,  the  feebly  developed  nervures  of  the 
females,  unfit  to  produce  audible  stridulations,  seem  to 
be  an  inheritance  from  the  males. 

Heredity  at  corresponding  periods  of  life  is  a  well- 
known  phenomenon.  The  tendency  to  disease  is  trans- 
mitted from  the  father  or  the  mother  to  the  child  to 
break  out  at  the  age  at  which  they  suffered.  Generation 
after  generation,  the  milk  teeth  make  room  for  the  per- 
manent teeth  at  a  corresponding  time.  But  all  special 
cases  are  mere  results  of  the  general  law  of  develop- 
ment, by  which  in  the  individual  characters  appear  in 
the  sequence  in  which  they  were  historically  acquired 
and  became  susceptible  of  transmission.  Heredity,  at  a 
definite  age  after  the  period  at  which  we  consider  actual 
development  to  be  complete,  is  after  all  only  a  continu- 
ation of  the  embryonic  development,  beginning  with 
fission,  germ  and  ovum,  of  which  the  ninth  chapter  will 
teach  us  the  signification.  In  this  development  of  the 
individual,  or   ontogenesis,  as  will  be  shown  below  in 


MUTABILITY.  I73 

more  detail,  processes  are  frequently  abridged  or  totally- 
omitted  which  once,  while  they  were  being  acquired 
and  after  they  had  been  established,  occupied  a  longer 
period,  but  in  the  course  of  selection  either  became  of 
less  importance  to  the  individual,  or  preserved  a  physio- 
logical value  only  as  phases  of  transition. 

The  second  great  class  of  characters,  namely,  those 
which  have  been  newly  acquired  and  depend  on  adap- 
tation, pre-suppose  the  mutability  of  the  organism. 
This  is  a  fundamental  phenomenon  of  organic  bodies. 
It  is  inherent  in  the  minutest  morphological  constituents, 
in  protoplasm,  and  in  cells,  and  in  the  morphological  ele- 
ments evolved  from  them,  the  pervading  and  determining 
individual  life  of  which  results  in  the  collective  life  of 
the  creature.  The  organic  morphological  element  is  in  a 
state  of  saturation  ;  it  is  continually  imbibing  and  emit- 
ting, and  its  stability  is  therefore  constantly  dependent 
on  the  supply  of  material  for  its  functions.  For  nutri- 
tion, which  generally  and  wholly  determines  the  external 
appearance  and  the  nature  of  the  individual,  is  accom- 
plished by  the  innumerable  cells  and  their  derivatives. 
Every  fluctuation  of  supply  to  any  part  of  the  organism, 
nay,  to  a  single  point  of  the  surface  of  a  microscopic 
atom,  must  involve  a  modification  of  textural  parts,  or  in 
the  structure  of  integrated  textural  groups  or  organs. 

Mutability  is  thus  a  character  resulting  from  the  in- 
trinsic nature  of  organism,  and  dependent  on  external 
conditions,  which  determine  quantity  and  form,  as 
well  as  the  development  and  transformation  of  the 
elementary  constituents,  or  their  abortion  and  retro- 
gression. These  efl"ects  may  be  exhibited  in  a  polype- 
stem,  which  as  a  whole   represents  the  individual,  in  its 


1/4  THE  DOCTRINE  OF  DESCENT. 

single  polypes,,  the  cells  and  morphological  elements. 
The  single  individuals  are  alike  in  their  constitution, 
but  are  usually  very  different  in  size  and  development, 
even  in  those  species  in  which  the  differentiation  un- 
questionably produced  by  selection  has  not  led  to 
polymorphism  or  separation  into  personal  groups  per- 
forming different  functions.  The  weal  or  the  woe  of 
our  polypes  is  greatly  dependent  on  the  position  which 
they  occupy  upon  tlie  stem ;  the  supply  of  nutri- 
ment primarily  furnished  to  the  single  individuals  is 
unequally  and  variably  apportioned  according  to  cur- 
rents and  tides.  Hence  on  each  polype-stem  there  are 
regions  where  the  single  polypes  are  especially  thriving, 
others  where  they  are  just  able  to  maintain  themselves, 
others  where  they  cannot  keep  their  balance.  But  as 
the  polype-stem  is  traversed  by  a  canal  system  convey- 
ing the  nutritive  fluid  and  connecting  the  several  cells, 
the  superfluity  of  the  well-situated  cells  goes  to  the 
benefit  of  those  for  whom  a  worse  lot  was  prepared  by 
their  accidental  position,  and  conversely.  These  rela- 
tions, which,  complex  as  they  seem,  are  very  simple  for 
our  comparison,  determine  the  form  and  appearance  of 
the  polype-stem.  Among  a  hundred  thousand  stems,  no 
two  will  be  found  absolutely  alike. 

To  return  to  the  mutability  of  organisms,  even  if 
two  individuals  of  the  same  species  are  bred  under 
the  most  similar  conditions  imaginable,  it  has  never 
been  possible  to  pronounce  them  absolutely  alike. 
That  mutability  is  slighter  in  lower  than  in  higher 
organisms,  is  a  prejudice  frequently  repeated  and  forti- 
fied by  the  old  dogma  of  species.  The  doctrine  of 
descent  and  selection  would  fare  ill  if  the  case  were 


ADAPTATION.  1/5 

SO.  But  as  the  shepherd  unerringly  knows  the  phy- 
siognomy of  his  sheep  where  an  excursionist  from  the 
town  sees  only  a  general  sheep's  face,  so  to  an  attentive 
naturalist,  in  most  of  the  lower  organisms,  the  specific 
type  resolves  itself  into  as  many  varieties  as  individuals, 
irrespectively  of  the  cases  in  which  no  specific  type  can 
be  established. 

As  modification  under  given  conditions,  adaptation  is 
thus  as  little  an  unknown  quantity  as  heredity,  but  is 
merely  a  function  of  the  mechanical  character  of  muta- 
bility, or,  in  the  widest  sense  of  the  word,  of  nutrition. 
Adaptation  takes  place  when  the  organism  or  its  parts 
are  pliable  and  plastic  to  external  influences,  when  they 
conquer  and  make  use  of  them.  Climate,  light,  humidity, 
nutriment,  are  hindrances  or  advantages  that  directly  or 
indirectly  affect  the  organism,  and  are  all  actively  con- 
cerned in  it.  Surrounded  by  organisms,  we  see  them 
without  exception  adapting  themselves  to  circumstances ; 
and  if  our  only  object  is  to  be  convinced  of  the  formative 
influence  of  the  mode  of  life,  this  is  most  readily  done 
in  the  case  of  domestic  animals.  In  his  studies  on  the 
pig,  H.  von  Nathusius,  perhaps  the  most  scientific  of  the 
celebrated  breeders,  shows  how  in  the  simplest  cases, 
where  the  looseness  of  cultivated  soil  has  facilitated  the 
labour  of  grubbing,  the  skull  of  the  domestic  pig  is  ar- 
rested, by  the  softer  structure  of  the  cranium,  at  the 
immature  form  of  the  wild  boar,  and  how  those  extreme 
shapes  of  the  head  in  cultivated  breeds,  characterized  by 
the  bending  and  shortening  of  the  face,  and  the  impossi- 
bility of  closing  the  jaw  in  front,  are  entirely  the  result 
of  their  altered  mode  of  life.  It  is  known  that  men, 
animals,  and  plants,  removed   far  from  their  previous 


176  THE   DOCTRINE  OF  DESCENT. 

abode  to  a  new  and  strange  environment,  after  a  longer 
or  shorter  effort  of  the  organism  to  domesticate  itself, 
either  die  out,  or  else  accommodate  themselves  to  the 
new  conditions  and  become  acclimatized.  Every  accli- 
matization is  therefore  an  adaptation,  accompanied  by 
modifications  more  or  less  perceptible.  Thus,  in  conse- 
quence of  the  varied  conditions  of  life,  there  is  a  wide 
divergence  among  races  of  men  who,  by  their  kindred 
language,  are  of  the  same  origin,  not  to  mention  those 
v/hose  relations  linguistic  inquiry  has  not  yet  decided. 
How  different  is  the  idiosyncrasy  of  the  Englishman 
from  that  of  the  Hindoo  !  Physically  and  psychically, 
they  represent  two  remarkable  sub-races  of  which  the  pe- 
culiarities must  be  ascribed  to  adaptation, — in  the  latter, 
to  a  climate  which  requires  a  vegetable  diet,  and,  eliciting 
neither  bodily  nor  mental  energy,  favours  a  dreamy 
sensuality ;  in  the  former,  to  a  country  which  is  in  every 
particular  the  opposite  of  the  Indian  original  home. 
Similarly,  the  annual  alternation  in  the  vital  phenomena 
of  so  many  organisms,  designated  as  hybernating  ani- 
mals, is  a  case  of  adaptation.  It  is  changed  the  moment 
the  organism  is  exposed  to  another  climate,  or  rather 
acclimatization  is  essentially  the  accommodation  of  the 
hybernating  animals  to  the  new  climate. 

In  all  these  examples  we  have  the  results  of  direct 
adaptation,  in  which  the  power  of  resistance  in  the 
individual  comes  into  play,  as  does  cumulative  adapt- 
ation in  artificial,  and  the  survival  of  the  fittest  in 
natural,  selection.  In  all  cases  of  adaptation,  one  or 
several  organs  are  primarily  concerned,  either  actively 
or  passively;  and  only  in  consequence  of  the  resulting 
modifications   are   the   other  organs   drawn   into  sym- 


CORRELATIVE  ADAPTATION.  1 7/ 

pathy.  Tliis  may  be  termed  correlative  adaptation.  It 
might  be  supposed  that  the  most  perspicuous  examples 
would  be  afforded  by  parasitic  animals,  in  which,  with 
the  alteration  of  the  aliment  and  of  the  alimentary 
apparatus,  especially  of  the  manducatory  portions,  is 
usually  combined  a  transformation  and  retrogression, 
often  extending  to  the  total  extinction  of  the  locomo- 
tive organs,  and  of  the  entire  segmentation  of  the  body. 
But,  although  the  limits  are  difficult  to  define,  the  cause 
of  these  associated  modifications  in  the  locomotive  and 
alimentary  apparatus  consists  less  in  their  reciprocal 
sympathetic  influence  than  in  their  simultaneous  disuse. 

It  is,  however,  by  correlative  adaptation  that,  for  in- 
stance, in  the  short-beaked  races  of  pigeons,  the  middle 
toe  and  astragalus  are  shortened,  and  that  in  the  long- 
beaked  races  these  organs  have  shared  in  the  elongation. 
In  the  case,  however,  in  which  short  beaks  are  combined 
with  short  feet,  a  certain  share  in  the  shortening  of  the 
feet  is  also  owing  to  disuse  ;  while  where  the  pigeon- 
fancier  took  pleasure  in  the  elongation  of  the  beak  by 
cumulative  selection,  the  correlative  elongation  of  the 
foot  took  place  in  spite  of  disuse.  The  most  important 
group  of  correlative  modifications  or  adaptations,  always 
using  this  word  in  its  widest  acceptation,  relates  to  the 
sphere  of  the  sexes.  Direct  attacks  on  the  generative 
organs  manifest  their  effects  on  all  the  rest  of  the 
organism,  as  is  best  shown  in  animals  of  both  sexes 
castrated  for  the  market  or  for  labour. 

We  have  already  seen  that  the  degree  of  perfection 
attained  in  the  orders  of  the  Articulata,  Annulosa 
Vertebrata,  and  partially  in  the  Radiata  also,  depends 
on  the  integration  of  the  originally  similar  parts  lying 


178  THE   DOCTRINE   OF   DESCENT. 

behind  or  by  the  side  of  one  another ;  hence  on  the 
division  of  labour.  This  Haeckel  has  designated 
divergent  adaptation.  It  gives  rise  to  the  remark- 
able polymorphism,  which  appears  especially  in  the 
marvellous  forms  of  the  Hydra  tuba ;  and,  higher  up,  in 
the  organization  of  the  communities  of  the  Termites  and 
the  Bee,  &c. 

So  far  as  modification  coincides  with  adaptation,  the 
direct  adaptations  hitherto  discussed  may  be  contrasted 
with  a  series  of  indirect  adaptations.  Among  these  may 
be  comprised  a  series  of  phenomena  of  which  the  causes 
do  not  fall  within  the  life  of  the  individual,  but  are  to 
be  sought  in  influences  by  which  the  parents  were 
affected.  It  is  obvious  that  we  here  come  into  contact 
with  the  province  of  heredity,  which  is  well  known 
to  breeders.  Thus  H.  v.  Nathusius,  in  his  studies  on 
the  formation  of  the  pig's  skull,''^  says  : — "  From  the 
facts  here  collected,  it  is  plain  that  the  transmission,  the 
transfer  of  the  form  of  head  from  the  parents  to  the 
offspring,  does  not  unconditionally  ensue.  If  the  form 
of  skull,  which  we  will  briefly  term  the  cultivated  form, 
be  the  product  of  nutrition  and  mode  of  life,  hence  of 
external  influence,— if  it  can  be  differently  formed  in  the 
same  individual,  and  is  therefore  not  constant, — in  that 
case  the  heredity  of  this  form  cannot  be  spoken  of 
without  qualification.  The  form  itself  will  not  be  trans- 
mitted to  the  offspring,  but  only  the  tendency  to  the 
form.  This  may  be  inferred  from  the  circumstance 
that  from  generation  to  generation,  and  to  a  certain 
degree,  the  form  increases  in  peculiarity.  If  we  rear  a 
common  with  a  thorough-bred  pig,  and  if  we  allow 
exactly   the   same   influences   of    nutriment   and   keeping 


MIMICRY.  179 

to  operate  upon  both,  and  in  equal  measure,  we  shall 
not  obtain  the  same  form  of  head.  The  development 
of  the  form  of  head  must  therefore  be  aided  by  a  pre- 
existing tendency,  and  we  must  hence  regard  it  as 
hereditary." 

Haeckel  likewise  propounds  a  law  of  individual 
adaptation,  which  expresses  the  fact  that,  notwith- 
standing the  closest  kinship,  individuals  diverge  in 
many  ways.  The  cause  of  this  difference,  chiefly  con- 
spicuous in  the  individuals  of  the  same  litter  or  brood, 
is,  so  far  as  it  is  not  due  to  adaptation,  inherent  in 
the  germs,  and  is  transferred  to  them  by  fluctuations 
and  differentiations  in  the  conditions  of  nutrition  in 
the  parents,  mostly  beyond  our  ken.  Other  phenomena 
of  indirect  adaptation  are  exhibited  in  the  occurrence 
of  malformations,  of  which  the  causes  must  be  looked 
for  only  in  disturbances  of  nutrition  in  the  parental 
organisms  by  which  the  progenitors  themselves  were 
not  perceptibly  affected.  Here  also  belong  the  cases 
in  which  influences  which  have  affected  one  sex  only 
are  manifested  exclusively  in  posterity  in  the  same 
sex.  As  may  be  seen,  these  processes,  of  which  the 
initiation  is  entirely  withdrawn  from  observation,  are 
closely  connected  with  the  most  obscure  province  of 
heredity. 

An  extremely  interesting  and  important  form  of 
adaptation  is  the  so-called  mknicry,  or  protection  by 
means  of  colouring  and  form.  The  first  discoveries 
on  this  subject  were  made  by  Bates,  the  well-known 
"Naturalist  on  the  Amazon;"  the  greater  part  were 
subsequently  added  by  Wallace.  In  South  America, 
the  family  of  butterflies  named  Heliconida   is   extra- 


f80  THE  DOCTRINE  OF  DESCENT, 

ordinarily  extensive;  they  are  remarkable  for  their 
elongated  wings,  body,  and  antennae,  and  for  the  beauty 
of  their  colours.  It  might  be  imagined  they  were 
exposed  to  the  persecutions  of  insectivorous  birds  and 
other  animals  ;  but  this  is  not  the  case,  for  they  have  a 
disagreeable  smell,  which,  in  all  likelihood,  renders  them 
obnoxious.  Their  smell  and  flavour  are  thus  a  protection, 
as  the  birds  and  lizards  who  have  once  seized  them  by 
mistake  are  certain,  ever  after,  to  leave  them  unmolested. 
Now,  as  the  insectivora  do  not  test  the  individual  case, 
but  have  adopted  a  general  repugnance  to  the  aspect  of 
the  Heliconidae,  if  other  butterflies  resembled  the  Heli- 
conidse  without  possessing  the  bad  smell,  they  would 
participate  in  the  security  to  life  enjoyed  by  the  Heli- 
conidae in  proportion  as  they  approach  their  external 
appearance.  This  case  has  actually  occurred,  for  Bates 
discovered  a  number  of  species  of  the  otherwise  very 
different  genus,  Leptalis,  of  which  each  almost  undis- 
tinguishably  resembles  one  of  the  Heliconidae  both  in 
colour  and  form.  The  Leptalidae  have  also  adopted  the 
flight  of  the  Heliconidae,  share  their  habitats,  and, 
although  without  the  offensive  smell,  fly  about  with 
impunity.  This  state  of  things  would  be  impossible  if 
the  Leptalidae  were  not  considerably  in  the  minority,  so 
as  to  be  in  a  measure  hidden  by  the  Heliconidae. 

Wallace  has  proved  that  species  protected  by  mimicry 
of  other  animals  are  invariably  in  the  minority,  and 
often  very  rare  in  comparison  with  the  species  which 
they  imitate.  Neither  the  explanation  that  like  condi^ 
tions  of  life  produced  like  results,  nor  the  hypothesis 
that,  in  some  cases  at  least,  the  mimicry  consists  in 
reversion  to  a  common  original  species,  is  in  any  way 


MIMICRY.  l8l 

satisfactory.  Many  cases  can  be  interpreted  only  by 
natural  selection,  those,  namely,  where  from  the  first, 
before  the  imitation  had  begun,  such  a  resemblance 
already  existed  between  the  imitating  and  imitated 
forms  as  to  render  confusion  possible  ;  where,  therefore, 
the  resemblance  so  conducive  to  the  preservation  of 
those  in  which  it  was  the  strongest,  needed  only  to  be 
increased  by  natural  selection.  Darwin""*  is  also  of 
opinion  "that  the  process  probably  has  never  com- 
menced with  forms  widely  dissimilar  in  colour." 

A  peculiar,  simpler  and  long  known  mimicrj^,  is  when 
animals  have  accommodated  themselves  in  colour  to 
their  habitats  in  such  a  manner  as  not  to  attract  the 
attention  of  their  enemies,  and  likewise  to  deceive  their 
prey.  Who,  in  the  days  when  he  chased  butterflies,  did 
not  learn  how  difficult  it  is  to  recognize  certain  evening 
and  nocturnal  flyers  on  the  bark  of  trees,  as  they  quietly 
sit  with  their  dusky  brown  or  gray-striped  or  speckled 
wings,  outspread  in  a  roof-like  shape.?  The  tree  locusts 
and  Mantidai  can  look  so  deceptively  like  leaves  or 
twigs,  that  it  is  only  by  the  touch  that  one  can  be 
assured  of  their  real  nature.  Wallace  relates  that  one 
of  the  Phasmidae  (Ceroxylus  laceratus),v/hich  he  obtained 
at  Borneo,  was  so  covered  with  pale  olive-green  excres- 
cences, that  it  looked  like  a  stick  covered  with  moss. 
The  Dyak  who  brought  him  the  animal  declared  that, 
although  alive,  it  was  really  overgrown  with  moss,  and 
tlie  naturalist  himself  was  only  convinced  of  the  con- 
trary by  tlie  closest  examination. 

A  remarkable  example  of  advantageous  colouring, 
within  easy  reach  of  many  of  our  readers,  is  exhibited 
in  most  species  of  the  flat-fish  (Pleuronectidae),  now  so 


1 82  THE  DOCTRINE  OF   DESCENT. 

frequently  kept  in  aquaria.  Observe  the  gray  or 
brownish  speckled  creatures,  as  with  a  few  strokes  of 
their  fins  they  partially  cover  their  upper  surface  with 
sand.  They  need  not  bury  themselves  entirely,  for  it  is 
only  by  close  examination  that  their  bare  skin  can  be 
distinguished  from  the  sandy  bottom,  and  under  this 
partly  artificial,  partly  natural  veil  and  mask,  the  animal 
waits  for  its  prey. 

In  many  animals  provided  with  protective  colouring 
the  phenomena  are  more  complex,  and  explanation 
by  natural  selection  is  far  more  difficult;  for  they  are 
able  voluntarily  to  adapt  their  colour  to  circumstances, 
or  else  their  colour  changes  by  involuntary  reflexes. 
Verany's  unsurpassable  observations  on  the  Cephalo- 
poda have  acquainted  us  with  the  range  of  colours 
at  the  disposal  of  these  Molluscs,  and  to  this  may  be 
be  joined  Brehm's  description  of  the  changes  of  colour 
in  the  chameleon.  On  these  highly  complex  cases 
some  light  is  thrown  by  the  simpler  instances  in  which 
the  manifestly  protective  colouring  has  become  fixed  in 
skin  and  plumage,  and  the  concurrence  of  other  circum- 
stances scarcely  admits  of  any  other  explanation  than 
selection. 

On  this  point,  Wallace's  interesting  researches  on  bird's- 
nests  are  especially  instructive.  The  great  majority  of 
female  birds  which  sit  in  open  nests  possess  brown  or  gray, 
in  short,  unobtrusive  plumage.  No  contradiction  will  be 
offered  to  the  statement  that  any  casual  modifications 
of  plumage,  which  would  more  readily  betray  the  sitting 
bird  to  its  enemies,  would  have  no  prospect  of  becoming 
constant.  The  converse  follows  naturally  with  regard 
to  colouring  which  brings  the  bird  into  harmony  with 


USE  AND  DISUSE  OF  ORGANS.  1 83 

Its  environment ;  and  an  important  guarantee  of  the 
correctness  of  this  interpretation  of  facts  is  afforded  by 
the  other  observation,  that  most  female  birds  with  gaily 
coloured  or  speckled  plumage  sit  in  covered  and  con- 
cealed nests.  It  must  be  added,  that  the  construction 
of  nests  is  not  determined  by  the  absolute  rules  of  a 
blind  instinct,  but  is  modified  by  the  experience  of  the 
animals,  an  experience  of  which  we  are  indeed  scarcely 
able  to  perceive  the  development,  except  with  the  age  of 
the  individual,  but  which,  at  least  in  several  cases,  has 
been  proved  to  be  the  progress  of  the  species. 

Natural  selection  has  an  important  accessory  in  the 
modifications  produced  by  the  use  or  disuse  of  organs. 
Compulsion  to  more  diligent  use,  inducements  to  dis- 
use, are  involved  in  the  varying  conditions  of  life.  In 
both  cases  it  is  therefore  a  question  of  adaptation. 
Looking  at  nature,  profound  modifications  are  most 
readily  demonstrated  as  the  consequence  of  disuse  ;  but 
artificial  selection  gives  numerous  examples  of  both 
sorts,  especially  where  disproportionate  use  of  certain 
organs  is  combined  with  simultaneous  disuse  of  others. 
Such  products  of  selection  with  disproportionate  use  are 
the  racer  and  the  dray-horse. 

The  blindness  of  cave  animals  admits  of  no  explana- 
tion, but  that,  with  the  increasing  uselessness  of  the  eyes 
during  accommodation  to  cave  life,  the  exchange  of 
material  in  the  less  active  organs  gradually  diminished, 
and  atrophy  was  initiated.  The  accuracy  of  these 
theoretical  observations  is  enforced  by  the  observation 
that  the  nearest  kin  of  many  blind  cave  animals,  espe- 
cially of  insects  and  spiders,  reside  in  the  vicinity  of 
the  cave,  and  that  those  cave  anim.als  which  inhabit  pas- 


1 84  THE  DOCTRINE  OF  DESCENT. 

sages  only  partially  obscure,  possess  less  atrophied  optic 
apparatus.  A  singular  gradation  occurs  among  the 
burrowing  mammals,  and  Darwin  ^^  cites  an  example 
admirably  illustrating  the  loss  of  sight  in  consequence 
of  the  mode  of  life.  "  In  South  America  a  burrowing 
rodent,  the  Tuco-tuco,  or  Ctenomys,  is  even  more 
subterranean  in  its  habits  than  the  mole  ;  and  I  was 
assured  by  a  Spaniard,  who  had  often  caught  them,  that 
they  were  frequently  blind  ;  one  which  I  kept  alive  was 
certainly  in  this  condition,  the  cause,  as  appeared  on 
dissection,  having  been  the  inflammation  of  the  nicti- 
lating  membrane.  As  frequent  inflamniation  of  the 
eyes  must  be  injurious  to  any  animal,  and  as  eyes  are 
certainly  not  necessary  to  animals  having  subterranean 
habits,  a  reduction  in  their  size,  with  the  adhesion  of  the 
eyelids  and  growth  of  fur  over  them,  might  in  such  case 
be  an  advantage  ;  and,  if  so,  natural  selection  would 
constantly  aid  the  effects  of  disuse  " 

In  the  classes  of  flying  animals,  a  large  number  have 
left  off  flying  ;  and  we  find  their  flying  apparatus  in  an 
aborted  or  incomplete  condition,  which  perverse  judg- 
ment and  reasoning  alone  can  regard  as  a  state  of 
progressive  development  from  yet  simpler  rudiments. 
If  throughout  the  great  family  of  the  Coleoptera,  genera 
and  species  are  to  be  found  with  imperfect  flying  appa- 
ratus, consolidated  wing  covers,  &c.,  if  the  whole  family 
of  Staphylinae  does  not  possess  the  power  of  flight,  no 
one  dreams  of  considering  them  as  arrested  forms; 
but  it  is  conceivable  that  the  mode  of  life  in  which 
they  differ  from  the  other  members  of  their  order  and 
class,  gradually  superinduced  in  their  flying  ancestry  the 
habit  of  not  flying,  and  at  the  same  time  the  atrophy 


USE  AND   DISUSE   OF   ORGANS.  I85 

of  the  organs  of  flight.  With  this  was  combined,  as 
these  beetles  show,  no  degradation  of  organization,  but, 
on  the  contrary,  a  higher  and  extremely  advantageous 
development  of  other  organs,  the  manducatory  and 
locomotive  apparatus.  A  general  reduction  of  the 
power  of  flight  has  been  shown  in  the  beetle  fauna  of 
many  islands.  Thus  in  Madeira,  of  550  species,  over 
200  fly  imperfectly  or  not  at  all,  and  for  this  there  is 
no  explanation  but  natural  selection.  Here  the  less 
good  and  enterprising  flyers  had  the  advantage,  while 
the  others  were  blovv^n  into  the  sea  and  eliminated. 
The  non-application  of  a  previously  attained  special 
perfection  is  advantageous  in  the  "  struggle  for 
existence." 

In  several  families  of  lizards,  some  genera  are  ser- 
pentine, as  they  are  termed,  which,  with  elongated 
bodies,  possess  either  fore-legs  only  (Chirotes),  or 
merely  rudimentary  hind-legs  (Pseudopus),  or  no  ves- 
tiges of  legs  (Anguis).  They  bear  the  same  relation 
to  the  great  class  of  normally  four-legged  lizards  as 
the  non-flying  insects  to  their  own  class.  They  have 
not  been  arrested  in  their  development,  nor  are  they 
animals  in  process  of  evolving  four  legs ;  but,  as 
Ftirbringer  has  demonstrated  from  the  history  of 
development  and  comparative  anatomy,  their  limbs, 
and — if  these  are  entirely  absent — the  remains  of  the 
pectoral  and  pelvic  arches  and  the  sternum  bear 
indubitable  marks  of  the  abortion  of  a  once  com- 
plete apparatus.  Further  comparison  shows  that  this 
atrophy  reaches  its  climax  in  the  snakes,  but  that  it 
is  compensated  for  by  the  ribs  and  intercostal  muscles 
liaving    undertaken    the    work    of    the    limbs.     Here, 


l86  THE  DOCTRINE  OF  DESCENT. 

again,  disuse  and  adaptation  coincide  as  well  as 
differentiation. 

In  the  class  of  birds  is  repeated  the  spectacle  we 
have  just  witnessed  in  beetles  and  reptiles.  In  some 
few  families  and  smaller  groups,  individual  species  are 
deprived  of  the  power  of  flight,  and  one  whole  large 
systematic  group  is  characterized  by  the  incapacity  of 
flying.  In  our  opinion,  there  was  a  direct  connection 
between  the  inducements  to  disuse  and  its  conse- 
quences in  the  case  of  the  dodo,  which,  with  its  few 
congeners,  so  promptly  fell  a  sacrifice  to  its  helplessness 
on  the  discovery  of  the  lonely  islands  which  they  had 
probably  inhabited  for  thousands  of  years  without  dis- 
turbance. In  no  other  way  has  the  northern  penguin 
(Alca  impennis)  at  some  time  obtained  the  curtailment 
of  its  wings  ;  and  the  scanty  but  wide-spread  remains  of 
the  order  of  flightless  birds  indicate  a  period  at  which, 
in  a  more  peaceful  environment,  their  far  more  nume- 
rous wingless  ancestry  made  less  use  of  their  pinions,  and 
natural  selection  endowed  them  with  greater  strength 
and  nimbleness  of  leg.  The  effects  of  disuse  of  the 
organs  of  locomotion  are  likewise  directly  exhibited  by 
artificial  selection. 

Use  and  disuse,  combined  with  selection,  elucidate 
the  separation  of  the  sexes,  and  the  existence,  otherwise 
totally  incomprehensible,  of  rudimentary  sexual  organs. 
In  the  Vertebrata  especially,  each  sex  possesses  such 
distinct  traces  of  the  reproductive  apparatus  character- 
istic of  the  other,  that  even  antiquity  assumed  herma- 
phroditism as  a  natural  primaeval  condition  of  mankind. 
The  technical  proofs  of  the  homologies  concerning  these 
partly  manifest,  partly  internal  and  hidden  relations,  are 


PARASITES.  187 

given  in  the  manuals  of  comparative  anatomy.  We 
shall  merely  indicate  the  manner  in  which  the  theory 
of  selection  is  here  borne  out.  It  is  self-evident  that 
in  hermaphrodite  animals,  fluctuations  in  the  sexual 
sphere  must  take  place,  in  which  one  half  or  the  other 
will  predominate.  Should  these  fluctuations  be  suffi- 
ciently strong  for  natural  selection  to  take  possession 
of  them,  the  productive  power  of  the  less  active  portion 
will  gradually  decrease,  and  finally,  with  the  extinction 
of  the  physiological  character  and  the  function,  nothing 
will  be  transmitted  but  the  morphological  remains,  as  a 
mockery  to  the  theory  of  special  design  or  teleology. 
Here  and  there  only  occurs  a  reversion .  more  or  less 
striking,  connected,  however,  almost  exclusively  with 
the  adjunctive  organs,  and  the  secondary  sexual  cha- 
racters, by  which  we  mean,  not  those  acquired  by  either 
sex,  but  originally  common  to  both.  The  tenacity 
with  which  these  rudiments  of  sexual  organs  are  in- 
herited is  very  remarkable.  In  the  class  of  mammals 
actual  hermaphroditism  is  unheard  of,  although  through 
the  whole  period  of  their  development  they  drag  along 
with  them  these  residues,  borne  by  their  unknown  an- 
cestry no  one  can  say  how  long. 

Unless  we  suppose  that  parasitic  animals  were  created 
simultaneously  with  their  hosts  from  the  dust  of  the 
earth, — man  and  his  tapeworm,  and  other  disagreeable 
guests, — and  thus  put  an  end  to  the  discussion,  this 
entire  province  has  to  be  explained  by  descent,  with 
the  special  co-operation  of  disuse.  The  proposition  to 
be  demonstrated  in  the  next  chapter,  that  the  evolu- 
tionary history  of  the  individual  represents  the  history 
of  the  species,  will  show  the  influence  of  the  disuse  of 


1 88  THE   DOCTRINE  OF   DESCENT. 

particular  organs  on  the  configuration  of  the  various 
parasites.  The  parasitic  Crustacea  are  perhaps  the  most 
instructive,  as  they  present  the  most  complete  systematic 
series,  exhibiting  the  gradual  atrophy  of  the  organs 
which  accompanies  the  ever-increasing  connection  of 
the  parasite  with  his  host.  In  several  orders  of  intes- 
tinal worms,  the  alimentary  canal  has  become  entirely 
unnecessary ;  but  they  exhibit  neither  intermediate 
forms  nor  phases  of  development.  It  is  different, 
however,  with  the  parasitic  Crustacean,  for  here  the 
young,  locomotive,  and  well-integrated  being  has 
its  prototype  in  definitive  generic  forms  permanently 
locomotive,  txom  which,  after  adhesion,  it  deteriorates 
into  a  mere  motionless  sac.  All  these  animals,  in- 
cluding the  intestinal  worms,  have  acquired  their 
position  and  status  (and  this  is  the  true  significance  of 
parasitic  life)  by  the  apparent  degradation  of  their 
organization.  They  are,  almost  without  exception,  dis- 
tinguished by  their  reproductive  power ;  and  on  this, 
owing  to  the  easy  supply  of  nutriment,  without  any 
exertion  of  the  other  parts  of  the  organic  system,  the 
whole  bodily  activity  could  be  concentrated. 

We  have  hitherto  demonstrated  that  organisms  are 
urged  to  continual  differentiation  by  the  unremitting 
struggle  for  existence.  For  the  cultivation  of  morpho- 
logical species,  natural  selection,  moreover,  seizes  on  the 
modifications  arising  from  the  mere  variability  of  the 
organism,  and  implying  no  physiological  advance.  But 
sooner  or  later  these  are  also  inevitably  drawn  into  the 
vortex  of  competition.  After  what  has  been  already 
said,  this  fact  is  so  self-evident  as  to  need  no  further 
proof      Even   dt'd  we  not   see    the    infinite  variety  of 


THEOLOGICAL  INFLUENCES  1 89 

organisms,  a  divergence  into  novelty  must  needs  be 
inferred  on  a  priori  grounds,  from  the  existence  of 
the  simple  and  uniform,  and  the  necessity  of  adapta- 
tion to  altered  external  conditions.  But  with  develop- 
ment in  various  directions,  under  the  guidance  of 
natural  selection,  progress  is  necessarily  combined.  It 
is  one  of  the  greatest  services  rendered  by  the  theory 
of  selection,  that  it  has  finally  broken  with  the  notion  of 
design,  which  hitherto  invested  the  organic  world  with 
perfection  externally  bestowed,  and  even  in  the  pro- 
vince of  intelligence  and  morality,  where  it  is  said  with 
Schiller, 

So  grows  the  Man  as  grow  his  greater  aims,* 

has  secured  admittance  for  the  uniform  method  of 
natural  science. 

It  is  highly  remarkable  how  the  teleological  view 
of  nature  could  be  so  long  upheld,  and  is  still  in 
part  upheld,  by  theological  influence  although  in  the 
whole  organic  world  we  behold  a  merely  relative  per- 
fection, and  the  manifest  and  multifarious  arrangements 
adverse  to  design  in  every  grade  of  organisms,  bear  a 
bad  testimony  to  the  external  directing  Power.  The 
perfection  exhibited  by  comparative  anatomy,  and  the 
estimate  of  physiological  functions  is,  under  all  circum- 
stances, the  result  of  adaptation  and  selection.  In  the 
struggle  of  all  against  all,  those  individuals  win  who 
in  any  degree  excel  their  fellows  in  the  division  of 
labour,  which,  if  the  direction  of  activity  be  altered, 
often  obliges  them  to  disuse  organs  which  were  once  of 
service,  but  in  the  new  conditions  are  useless,  and,  it 
may  be  generally  said,  have  become  injurious. 

*  Els  wiichst  der  Mensch  mit  seinen  grussem  Zwecken. 


igO  THE  DOCTRINE   OF  DESCENT. 

Artificial  selection — and  here  we  may  speak  of  design 
— produces  perfection  when,  by  mechanical  and  physio- 
logical labour  (the  latter  especially  by  means  of  suit- 
able nutriment),  it  exercises  the  particular  parts  which 
are  to  be  perfected,  and  propagates  the  advantages 
obtained.  What  we  term  natural  selection  is  the  epitome 
of  the  improvements  acquired  by  specialization  in  the 
process  of  adaptation.  The  most  faithful  image  of  this 
gradually  acquired  specialization  is  afforded  by  the 
development  of  the  individual,  where  from  the  undif- 
ferentiated, by  constantly  increasing  differentiation,  the 
mature  animal  is  evolved  in  the  plenitude  of  its  physio- 
logical functions.  That  in  the  various  animal  groups 
certain  grades  of  perfection  are  attained,  is  an  uncon- 
troverted  fact ;  but  every  closer  investigation  shatters 
the  idol  of  design.  The  organism  of  the  bird  might 
induce  us  to  consider  it,  in  the  abstract,  as  modified 
for  the  purpose  of  flight.  But  if  design  be  allowed  to 
watch  over  the  good  flyers,  the  idea  of  design  must  be 
abandoned  with  respect  to  the  non-flyers,  and,  if  some 
idea  is  indispensable,  adaptation  must  have  its  due. 
Herewith  the  whole  theory  is  broken  down,  and  it  will 
be  the  same  in  every  other  case. 

How  organic  perfection  stands  with  reference  to  the 
idea  of  design,  has  been  acutely  and  clearly  expressed  by 
the  author  of  the  "  Unconscious  "  ('*  Das  Unbewussten  "). 
The  theory  of  descent  teaches  that  there  is  no  inde- 
pendence of  the  conditions  co-operating  in  an  organic 
phenomenon  ;  rather  that  its  increasing  divergence  from 
a  common  neutral  point  was  an  effect  of  the  same  causes. 
The  theory  of  selection  makes  us  acquainted  with  one 
of  these  causes,  and  unquestionably  the  most  important 


FITNESS  WITHOUT  DESIGN.  IQl 

as  one,  which,  by  purely  mechanical  compensative  phe- 
nomena, produces  advantageous  results.  The  theory  of 
descent  merely  casts  doubts  on  the  teleological  principle 
by  withdrawing  the  basis  for  positive  proof,  but  the 
doctrine  of  selection  sets  it  directly  aside,  so  far  as  it  is 
able  to  extend  its  explanation.  For  natural  selection 
in  the  struggle  for  existence,  the  extermination  of  the 
less  appropriate,  and  the  survival  and  perpetuation  of  the 
fittest  and  most  appropriate,  is  a  process  of  mechanical 
causality  of  which  the  steady  conformity  to  law  is 
nowhere  infringed  by  any  teleological  controlling  meta- 
physical principle.  This,  however,  produces  a  result 
essentially  corresponding  to  design  ;  that  is  to  say,  it 
naturally  bestows  on  organisms  the  highest  capacity 
for  life  under  given  circumstances.  Natural  selection 
solves  the  apparently  insoluble  problem  of  explaining 
fitness  as  a  result,  without  calling  in  the  aid  of  design 
as  a  principle. 

In  each  family — for,  as  we  have  seen,  what  zoologists 
once  designated  type,  has  in  the  doctrine  of  Descent 
become  the  family — in  each  family  lies  the  potentiality 
of  a  certain  grade  of  perfection ;  and  when  the  main 
outline  of  the  family  character  is  established,  we  see  a 
development  taking  place,  of  which  the  potentiality  is 
inherent  in  the  tendency  of  the  character,  the  realization 
and  necessity  in  the  external  conditions.  Hence  to  us 
also,  progress  is  development,  but  not  towards  a  pre- 
destined and  pre-established  harmony.  Karl  Ernst  v. 
Baer,^*  anxious  to  rescue  design,  or  at  least  the  "  pur- 
pose"— in  short,  predestiny,  in  the  evolutionary  series  of 
Nature,  says  :  "  Every  cause  engenders  a  process  which 
again  works  on  towards  another  purpose."     But  why 


igz  THE  DOCTRINE   OF   DESCENT. 

purpose  ?  Ought  it  not  rather  to  be :  Every  causa 
engenders  a  process  which  again  works  on  towards 
another  process  ?  The  further  we  go  back,  the  deeper 
and  more  general  is  the  grade,  and  the  various  ramifica- 
tions at  their  peripheral  ends  have  either  halted,  or 
arrived  at  very  different  grades. 

An  objection  frequently  made  against  this  result  of 
the  doctrine  of  Descent  is,  that  if  all  are  pressing  for- 
ward towards  perfection,  how  is  it  that,  besides  the 
higher,  so  many  lower  members  of  the  family  are  able 
to  maintain  themselves,  and  how  can  the  lower  families 
hold  their  own  against  the  higher,  in  the  struggle  for 
existence  ?  In  presence  of  the  irrefutable  facts  of  pro- 
gress, it  is  enough  to  point  out  that  the  lower  forms 
could  and  can  continue  to  exist  wherever  they  could 
find  space  as  well  as  the  other  necessaries  of  life. 
While  they  here  underwent  only  slight  modifications, 
elsewhere  the  needful  selection  led  to  more  profound 
metamorphoses ;  and  on  a  subsequent  geographical  dis- 
placement, the  newly  transformed  beings,  accustomed  to 
other  conditions  of  existence,  were  again  able  to  share 
sea  and  land  with  the  stationary  species.  For  as  diver- 
sity is  restored  now  by  selection,  and  the  demands  for 
nutriment  and  other  necessaries  are  likewise  different, 
a  partial  remission  in  the  struggle  must  take  place. 

The  preservation  of  a  great  many  inferior  organisms 
is  evidently  favoured  by  the  circumstance  that  just  De- 
cause  they  are  simpler,  their  propagation  is  more  easily 
effected.  Hence  although,  especially  in  limited  districts, 
amid  violent  competition  of  superior  varieties,  countless 
species  must  suffer  extirpation,  yet  the  struggle  for 
existence  and  perfection  do  not  exclude  the  existence 


CHANCE.  193 

of  lower  forms.  But  teleology,  as  it  seems  to  us,  still  fails 
to  explain  what  has  been  explained  by  the  theory  of  selec- 
tion. The  retardation  of  the  lower  organisms,  notwith- 
standing the  internal  pressure  and  the  appointed  purpose, 
is  incomprehensible. 

But,  it  is  frequently  asked,  if  you  will  not  hear  of 
a  "principle  of  perfectibility"  inherent  in  organisms 
(Nageli),  of  the  "  divine  breath  as  the  inward  impulse 
in  the  evolutionary  history  of  nature"  (Braun),  of 
**  tendency  to  perfectibility  '*  implanted  by  the  Creator 
(R.  Owen),  even  of  the  "  striving  towards  the  purpose  " 
(v.  Baer),  can  chance  be  supposed  to  have  produced 
these  marvellous  higher  organizations  ?  To  this  it  may 
be  plainly  answered,  that  this  chance,  to  which  purblind 
humanity  allots  so  great  a  part  wherever  the  personal 
interference  of  a  superior  Being  or  the  universal  "  crea- 
tive and  productive  principle "  is  not  at  hand,  has  no 
existence  in  nature,  and  that  our  conviction  of  the  truth 
of  the  doctrine  of  derivation  is  due  to  its  adjustment 
of  the  phenomenal  series  as  causes  and  effects.  Let 
us  remember,  and  fancy  ourselves  in  possession  of,  the 
formula  of  the  universe  of  Laplace,  by  the  aid  of  which 
all  future  evolutions  might  be  computed  in  advance. 
With  our  limited  powers,  it  is  true,  it  is  retrospec- 
tively alone  that  certainty  can  be  approached  in  the 
calculation  and  discrimination  of  the  series.  In  this 
we  must  obliterate  the  word  chance,  for  causality,  as  we 
understand  it,  makes  chance  entirely  superfluous.  Any 
one  who  transports  himself  to  the  commencement  of  an 
evolution,  who,  for  instance,  fancies  himself  present  at 
the  genesis  of  the  reptiles,  may,  from  his  antediluvian 
observatory^  look  upon  the  development  of  the  reptile 


194  THE  DOCTRINE  OF   DESCENT. 

Into  the  bird  as  a  "chance,"  if  he  does  not  peradvcnture 
regard  it  as  predestined.  To  us,  who  trace  the  bird 
backwards  to  its  origin,  it  seems  the  result  of  mechanical 
causes. 

Let  lis  now  recapitulate  what  we  have  gained  by 
the  doctrine  of  Descent,  based  on  the  theory  of  selec- 
tion ;  it  is  the  knowledge  of  the  connection  of  organisms 
as  consanguineous  beings.  The  greater  the  accordance 
of  internal  and  external  characteristics,  the  closer  is  the 
kinship.  The  further  we  trace  the  pedigree  to  its  origin, 
the  fewer  become  the  characters  persisting  to  these 
roots,  the  more  do  these  characters  reveal  themselves  as 
acquisitions  in  the  lapse  of  time.  It  is  by  eliminating 
these  acquisitions  and  restricting  the  inherited  characters 
more  and  more  as  we  feel  our  way  backward,  that  we 
are  enabled  to  reconstruct  the  pedigrees  of  the  various 
groups.^^ 

We  do  the  very  thing  which  in  linguistic  inquiry  is 
deemed  extremely  natural  and  scientific.  The  ideas  and 
words  common  to  the  individuals  of  a  linguistic  family 
are  the  inheritance  from  the  intellectual  and  linguistic 
property  of  the  original  people,  from  which  the  pedigree 
of  the  family  has  ramified.  This  so-called  *'  chance  "  pre- 
vailed in  the  formation  of  the  derived  languages  neither 
more  nor  less  than  in  the  evolution  of  organisms  from  their 
original  forms. 


IX. 

Tlifc  Development  of  the  Individual  (Ontogenesis)  is  a  Repetition  of  the 
Historical  Development  of  the  Family  (Piiylogenesis) . 

Although  the  palaeontological  record  is  full  of  gaps, 
it  is  nevertheless  unmistakable,  as  even  most  of  the 
opponents  of  the  doctrine  of  Descent  are  ready  to  admit, 
that  from  the  older  to  the  more  recent  period,  a  progress 
takes  place  from  the  lower  to  the  higher  grades  of 
organisms,  which  is  likewise  exhibited  in  the  system  of 
the  present  vegetal  and  animal  world ;  and  that  in 
many  ways  embryonic  development  as  well  as  meta- 
morphosis and  heterogenesis, — in  a  word,  individual 
development  ("  Ontogenesis,"  Haeckel)  suggests  a  com- 
parison with  these  palaeontological  series,  as  well  as 
with  the  systematic  order  of  succession.  The  paral- 
lelism of  the  palaeontological  and  the  systematic  series 
is  either  a  miracle,  or  it  may  be  accounted  for  by  the 
doctrine  of  Descent.  There  is  no  other  alternative. 
And  the  doctrine  of  Descent  fully  bears  the  test ;  it 
shows  how  the  derivation  of  the  present  organisms  from 
those  previously  existing  rests  on  the  transmission  of 
the  characters  of  the  progenitors  to  the  offspring  and 
the  acquisitions  of  the  individuals.  The  phenomena  of 
individual  development  or  Ontogenesis  admit  of  no  other 
choice  ;  either  they  remain  incomprehensive,  or  they 
14 


ig6  THE  DOCTRINE  OF  DESCENT. 

Stand  the  test  of  the  doctrine  of  Descent  and  submit  to 
the  great  general  principle. 

If  we  scrutinize  the  countless  facts  of  reproduction  and 
development,  they  certainly  admit  of  classification  ;  they 
range  themselves  in  analogous  and  homologous  groups  ; 
types  of  development  become  apparent ;  we  speak  of 
development  without  metamorphosis,  of  transformation, 
and  heterogenesis.  But  what  necessary  relation  the 
alternating  forms,  the  shapes  appearing  in  heterogenesis, 
bear  to  the  complete  animal  or  the  sexually  developed 
chief  representative  of  the  species  ?  why  so  many  animals 
undergo  no  transformations,  but  emerge  "  complete  "  from 
the  egg  ?  why  the  species  belonging  to  the  same  class 
or  *'  type  "  possess  the  same  type  of  development  and 
process  of  construction  } — these  and  similar  questions  as 
to  the  interpretation  of  the  tangled  mass  of  facts  press 
themselves  upon  us.  And  they  are  also  tests  of  our 
theory  of  derivation.  The  doctrine  does  as  much  as  has 
been  done  by  any  great  hypothesis  in  its  special  applica- 
tion ;  and  if  it  gives  a  satisfactory  reply  to  all,  or  at 
least  to  nearly  all,  pertinent  questions,  these  are  so  many 
witnesses  and  proofs  of  its  truth,  which,  according  to  all 
scientific  custom  and  justice  and  philosophic  method, 
will  remain  valid  until  the  falsity  of  the  inductions  and 
inferences  has  been  demonstrated  and  a  better  hypothesis 
substituted  in  its  stead. 

The  first  proposition  derived  from  the  doctrine  of 
Descent  in  explanation  of  the  facts  of  individual  de- 
velopment may  run  thus  :  accordance  in  the  outlines 
of  development  is  based  on  similar  derivation;  or, 
somewhat  differently  stated :  accordance  in  the  out- 
lines of   individual  development    is    accounted  for    by 


DEVELOPMENT  OF  ECHINODERMS.       I97 

similarity  of  derivation.  As  we  already  know,  C.  E. 
V.  Baer  first  demonstrated  that  the  members  of  the 
great  divisions  of  the  animal  kingdom  agreeing  in  the 
outlines  of  their  organization  testify  their  coherence  by 
a  special  "type  of  development."  This  fact  was  always 
looked  upon  as  self-evident,  although,  if  it  were  not 
derived  from  descent,  it  would  be  the  greatest  miracle. 
This  is  therefore  the  place  for  us  to  review  some  of  the 
fundamental  forms  of  development  which  we  partially 
considered  in  the  third  chapter,  and  at  the  same  time 
to  elucidate  the  meaning  of  these  types  with  the  aid  of 
the  doctrine  of  derivation. 

We  will  take  the  Echinoderm  as  our  first  example. 
Although  from  the  anatomical  comparison  of  a  crinoid, 
a  star-fish,  a  sea-urchin,  and  a  sea-cucumber  or  holothuria, 
the  close  kindred  of  these  various  divisions  of  echino- 
derms  is  easily  deduced,  they  yet  deviate  wonderfully 
from  one  another  in  outward  shape  and  in  the  construc- 
tion of  the  skeleton.  The  relative  value  of  the  difference 
between  a  holothuria  and  a  star-fish,  a  sea-urchin  and  a 
comatula,  may  be  compared  to  the  difference  between 
a  mammal  and  a  bird,  an  amphibian  and  a  fish.  Never- 
theless, with  some  few  exceptions  which  have  a  special 
meaning,  these  various  echinoderms  leave  the  egg  in  a 
larval  state  almost  identical.  The  larva  (Fig.  12)  is 
boat-like  in  form,  with  a  curved  mar- 
gin bent  over  at  both  ends  like  a 
deck.  This  border  is  edged  with  a 
continuous  row  of  cilia,  by  the  agency 
of  which  the  little  boat  is  moved.  A 
short  digestive  canal,  provided  with  fig.  12. 

a  gastric  enlargement,  is  the  first  essential  organ  of  this 


198  THE  DOCTRINE  OF   DESCENT. 

body.  We  will  not  describe  the  highly  complex  transfor- 
mations of  the  larva  here  into  an  ophiura,  there  into  a 
sea-urchin,  and  here  again  into  a  sea-cucumber  ;  but  we 
will  only  inquire  what  can  be  the  cause  of  this  accord- 
ance in  the  earliest  stages  of  individual  development. 
There  is  no  reasonable  answer  but  the  derivation  of  all 
echinoderms  known  to  us  from  an  older  form,  in  the 
development  of  which  our  larva  likewise  appeared,  and 
from  which  this  common  phase  of  development  was 
transmitted  to  the  whole  family.  But  it  is  allowable  to 
ask,  further,  how  from  a  bilateral  larva,  one,  that  is, 
symmetric  on  two  sides,  should  be  evolved  in  animals 
of  radiate  structure,  as  are  the  greater  number  of  mature 
echinoderms  ? 

On  this  poiiit  Haeckel  instituted  a  conjecture  which 
at  first  exasperated  the  systematizers  of  the  old  school, 
but  which  now  gains  more  and  more  footing,  and  is  sup- 
ported by  the  most  recent  comparative  investigations, 
such  as  those  of  Hoffmann  "  On  the  Minute  Anatomy 
of  the  Starfish "  ("  Ueber  die  feinere  Anatomic  der 
See-sterne").  The  boat-shaped  larva  of  the  Echino- 
derms, especially  a  modification  occurring  in  the  star- 
fish, strikingly  resembles  a  certain  larval  type  of  the 
marine  Annehda.  And  as  in  the  structure  and  distribu- 
tion of  the  parts  of  the  rays  of  the  echinoderms,  espe- 
cially of  the  star-fish,  an  unmistakable  resemblance  with 
the  relative  distribution  and  succession  of  parts  of  the 
Annelids  is  observable,  Haeckel  regards  the  Echinoderms 
as  an  offshoot  of  the  Annelids.  He  considers  that  the 
oldest,  and  to  us  unknown,  echinoderms  originated  as 
annelid  stems  ;  the  anterior  end  of  the  bilateral  annu- 
lose  parent-animal  buddmg  out  gemmule.s  in  a  radiate 


DEVELOPMENT  O?  MOLLUSCS.  I99 

arrangement.  This  gemmation,  or,  in  other  words,  this 
stem  structure,  still  occurs  in  Echinoderms,  inasmuch  as 
some  species  of  star-fish  possess  such  powers  of  repro- 
duction as  to  enable  a  single  arm  or  ray,  when  torn  off,  to 
complete  itself  into  a  whole  animal.  Nay,  Kowalewsky's 
observations  render  it  highly  probable  that  the  separa- 
tion of  rays,  and  their  completion  by  gemmation,  is  in 
some  species  a  normal  process.  Haeckel's  hypothesis 
is  thus  laughed  at  only  by  those  who  are  afraid  to  think 
or  reason. 

In  the  family  of  the  Mollusca,  the  so-called  navicula 
larva  testifies  the  kinship  of  at  least  two  of  the  great 
classes.  The  third  and  most  advanced  class,  that  of 
the  cuttle-fish,  had  perhaps  lost  their  distinctive  badge 
even  in  those  primaeval  times  when,  under  the  somewhat 
lower  forms  of  the  Tetrabranchiata,  they  left  their  shells 
in  the  Silurian  strata.  But  the  bivalve  shells,  or  Lamelii- 
branchiata,  and  the  snails,  widely  differing  in  anatomical 
development,  and  constituting  two  natural  classes,  have 
a  common  larval  form,  or,  if  the  larvse  display  different 
shapes,  a  highly  distinctive  common  larval  organ,  the 
velum.  The  accompanying  diagram  gives  on  the  right 
the  navicula  of  a  cockle-shell  as  seen  from  behind.  At 
the  anterior  end,  two  fleshy  lobes  have  been  formed, edged 
with  cilia,  by  the  vibrations  of  which  the  young  animal, 
even  in  the  egg,  performs  spiral  twisting  motions  ;  in 
the  midst  of  the  cilia  rises  a  little  prominence,  furnished 
with  a  longer  filament.  These  ciliated  lobes  or  vela, 
merging  into  one  another,  are  shown  on  the  left  in  the 
larva  of  a  sea-snail  (Pterotrachea),  as  seen  nearly  in 
profile,  and  in  the  phase  in  which  the  eyes  and  auditory 
apparatus,  the  foot  and  operculum,  as  well  as  a  delicate 


200 


THE   DOCTRINE   OF   DESCENT. 


shell,  have  made  their  appearance.  Here  also,  from  the 
plane  of  the  velum,  a  small  fleshy  protuberance  juts  out, 
without  any  special  purport.  The  distribution  of  the 
velum,  the  period  at  which  this  larval  organ  makes  its 


Fig.  13. 


appearance,  its  position  towards  the  testa,  head,  mouth, 
and  foot,  and  its  subsequent  effacement,  one  and  all 
coincide  exactly  in  the  two  classes.  It  is  as  yet  of  only 
a  relatively  small  number  of  marine  shells  and  slugs 
that  we  know  the  evolutionary  history;  yet  we  may  infer 
that  in  these  animals  remaining  in  their  original  home, 
this  heirloom  has  been  generally  preserved.  Even  genera 
which  in  their  mature  state  scarcely  recall  the  type  of 
the  Mollusca,  as  the  boring  mollusks  (Dentalium  Teredo), 
have  preserved  the  phase  of  the  navicula.  On  the  other 
hand,  in  the  branchiate  fresh-water  snails  (Paludina) 
the  velum  is  little  developed,  and  in  the  land  snails, 
which  differ  most  widely  from  their  marine  kindred,  the 
velum  is  entirely  obliterated,  as  it  is  also  among  fresh- 
water mussels.  If  in  these  animals  adaptation  and 
migration  to  land  has  had  this  effect  on  embryonic  and 
post-embryonic  development,  we  must  suppose  that  in 


OTHER  FORMS  OF  DEVELOPMENT.       20I 

the  Cephalopoda,  notwithstanding  their  continued  so- 
journ in  salt  water,  other  causes  have  produced  the  loss 
of  the  velum  phase,  and  the  course  of  development 
peculiar  to  it 

With  respect  to  the  other  fundamental  forms  of  de- 
velopment, we  may  refer  to  the  third  chapter.  The 
construction  of  the  higher  Articulata  points  to  annulose 
progenitors,  more  or  less  corresponding  to  the  annelids 
of  present  times  ;  and,  again,  the  gradual  increase  of  the 
segments  of  the  larval  annelids,  which  may  be  com- 
pared to  the  process  of  gemmation,  leads  from  these 
higher  Vermes  to  the  lower  ones  with  unsegmented 
bodies.  All  vertebrate  animals,  man  included,  if  they 
do  not  preserve  through  life  an  unsegmented  vertebral 
column,  not  separable  into  single  vertebrae,  are  raised 
as  embryos  from  this  condition  into  their  higher  and 
definitive  phase.  The  fact  that  they  pass  through  this 
common  embryonic  condition  excludes  all  other  me- 
chanical causes  but  that  of  a  common  derivation  from 
primordial  forms  which  possessed  an  unsegmented 
vertebral  column,  no  cranium  or  an  imperfect  one,  and 
either  no  brain  or  one  little  differentiated  from  the 
spinal  cord.  Karl  Ernst  v.  Baer,  who,  while  we  write 
these  pages,  raises  his  voice  against  the  doctrine  of 
Descent,  has  established  the  fact  of  types  of  develop- 
ment, and  the  course,  within  these  types,  from  the 
undifferentiated  to  the  special ;  but  by  the  words 
**  type  of  development,"  the  fact  is  paraphrased,  not  ex- 
plained; and,  as  we  cannot  repeat  too  often,  we  prefer 
the  distinct  idea  of  derivation  to  the  supposition  of 
an  unknown  higher  Power  manifesting  itself  after  an 
incomprehensible  fashion  in  the  types  of  development. 


202  THE   DOCTRINE  OF  DESCENT. 

If  the  concatenation  of  the  series  by  direct  derivation 
and  heredity  be  disallowed,  it  is  absolutely  inconceiv- 
able why  the  supreme  creative  Power,  Nature,  or  the 
personal  God,  should  have  bound  all  higher  animals  to 
the  same  common  stages  of  early  development,  and  here- 
by exposed  them  to  such  manifold  purposeless  arrange- 
ments and  great  dangers.  Of  the  millions  of  young 
oysters  which  annually  escape  from  the  egg,  the  majo- 
rity perish  under  the  disadvantages  of  external  condi- 
tions, because  the  oyster  has  not  yet  divested  itself  of 
the  ancient  heirloom  of  the  roving  navicula.  It  has 
been  able  to  compete  successfully  in  the  struggle  for 
existence,  only  because,  like  most  of  its  congeners,  it  is 
enormously  prolific.  This  may  be  understood  ;  but  that 
a  personal  Creator,  merely  on  principle,  in  order  to  keep 
the  oyster  within  the  type  of  development,  should  have 
endowed  it  with  the  phase  of  the  navicula,  in  this  case 
so  extremely  unpractical,  can  be  accepted,  like  much 
other  nonsense,  only  as  matter  of  faith. 

If  accordance  in  the  outlines  of  development  has 
generally  shown  itself  derivable  from  similarity  of  de- 
scent, we  may  now  proceed  to  the  explanation  of  those 
phenomena  of  development  known  to  us  as  hetero- 
genesis  and  metamorphosis.  In  these,  the  historical 
stages  of  development  of  whole  classes  and  orders  are 
inherited  in  the  development  of  the  individual ;  a  pro- 
position which  is  merely  the  corollary  and  application  of 
what  has  been  already  intimated.  The  Hydromedurae 
offer  numbers  of  such  instances  of  heterogenesis,  of 
which  Gegenbaur's  early  views  gives  the  following  ac- 
count :  We  have  already  (p.  43)  become  acquainted 
with  the  origin   of   the  Cladonema   from  the  polype-like 


ALTERNATION   OF   GENERATIONS. 


203 


Stauridiuin.  The  Medusa  is  the  sexually  mature  foiTn  of 
the  cycle  of  the  species  ;  its  ova  develope  into  polypes, 
which  constitute  the  intermediate  form  in  their  develop- 
ment;   that  is    to  say,  it  is   not  transformed   into  the 


Fig.  14. 


animal  from  which  it  is  derived,  but  produces  gemmules. 
Only  in  this  generation  does  the  species  revert  to  the 
sexual  form. 

We  shall  understand  this  alternation  of  generations 
if  we  begin  with  the  simplest  Medusa  polypes.  Such 
a  one  is  the  annexed  Hydractinea  carnea,  of  which 
the  female  individual  is  portrayed.  Compared  with 
the  intermediate  form,  Stauridium,  the  preliminary 
phase  of  the  Cladonema,  reproducing  itself  asexually. 


204 


THE   DOCTRINE   OF   DESCENT. 


the  Hydractinea  seems  superior,  inasmuch  as  it  is  itself 
a  sexual  form.  The  zone  of  spherical  protuberances  in 
the  middle  of  the  body  are  the  ovaries  or  egg  capsules 
corresponding  to  the  sperm  capsules  of  the  male  indi- 
vidual. Heterogenesis  does  not  take  place  in  our  Hy- 
dractinia,  but,  as  in  the  development 
of  the  ovum  of  the  Cladonema  into  the 
Stauridium,  there  is  a  transformation 
of  a  ciliated  lava  into  a  sessile  polype. 
But  it  is  obvious  that  the  part  which 
in  the  Hydractinia  is  played  by  the 
male  and  female  sexual  organs  is  per- 
formed in  the  generative  cycle  of  the 
Cladonema  by  the  sexual  animals.  By 
following  the  transition  from  the  de- 
pendent organ  into  the  independent 
animal,  we  find  the  solution  and  ex- 
planation of  the  process  termed  he- 
terogenesis. Between  the  genera  reproduced  like  the 
Hydractinia,  and  those  reproduced  like  the  Cladonema, 
there  are  many  others,  of  which  the  propagation  shows 
the  gradual  transition  of  the  rudimentary  sexual  organs 
into  the  sexual  animal.  We  may  so  arrange  the  genera 
of  the  "  Medusa  polypes"  as  to  exhibit  how  the  parts 
which  in  the  Hydractinia  are  mere  capsules,  generating 
and  enclosing  the  ova,  become  more  and  more  perfect. 
They  acquire  a  special  branch  of  the  alimentary  canal 
and  blood-vessels,  and  are  provided  with  the  marginal 
papillae  characteristic  of  the  Medusae,  and  constituting 
their  peculiar  sensory  organs.  In  short,  what  in  one 
member  of  the  systematic  series  may  be  termed  an 
organ,  is,  in  the  next,  the  Medusa  separating  itself  and 


Fig.  is. 


PARASITIC  WORMS.  205 

becoming  a  new  generation  ;  the  sexual  organ  has 
become  the  sexual  animal. 

Now  as  the  individual  development  of  the  Clado- 
nema,  and  other  Medusae  similarly  propagated,  corre- 
sponds with  the  systematic  series  of  the  Medusa  polypes, 
the  only  reasonable  and  credible  explanation  of  the 
ontogenesis  of  those  Medusae  in  which  heterogenesis 
occurs,  is  that,  in  them,  the  historical  development  of 
the  genus  has  become  fixed.  Neither  the  egg  nor 
the  hen  was  created.  Before  the  deHcately  tinted 
Medusae  populated  the  primaeval  ocean  in  lonely  splen- 
dour, the  Medusa  polypes  on  the  constantly  changing 
shores  were  the  sole  representatives  of  the  still  infant 
class.  Another  and  very  reasonable  view  is  that  which 
Weisman's  latest  researches  tend  to  support  :  That 
polypes  were  indeed  the  precursors  of  the  Medusae ; 
that  individual  polypes  (not  merely  organs)  became 
Medusae,  and  that  the  imperfectly  developed  intermediate 
forms  were  degenerate  Medusae,  degraded  to  the  condition 
of  apparently  mere  organs. 

The  evolutionary  history  of  the  intestinal  worms  leads 
to  the  same  reflections  and  results.  These  animals, 
widely  differing  in  their  structure,  were  either  created  in 
or  with  their  hosts,  or  else  they  have  become  habituated 
to  them  in  a  natural  and  direct  manner.  We  may  surely 
disregard  the  third  alternative,  that  they  were  led  by 
an  innate  "  obscure  impulse."  According  to  our  doctrine, 
the  worms  now  passing  the  whole  or  a  portion  of  their 
lives  as  parasites  on  or  in  other  organisms,  are  descended 
from  free  and  independent  animals,  and  the  periods  oc- 
curring in  their  development,  during  which  parasitic  life 


206  THE  DOCTRINE  OF  DESCENT. 

is  exchanged  for  independent  phases,  signifies  a  rever- 
sion taking  place  systematically  in  all  individuals  to  the 
once  permanent  condition  of  their  progenitors.  Of  the 
Trematoda  or  Flukes,  and  Cestoda  or  Tapeworms,  be- 
longing to  the  class  of  the  Platelmintha  Suctoria,  the 
latter  have  diverged  the  most  from  their  starting-point  ; 
their  adaptation  to  life  within  other  animals  has  rendered 
the  alimentary  canal  superfluous,  and  their  generations 
and  transformations  hence  point  less  to  their  progenitors 
than  is  the  case  with  a  number  of  other  Trematoda,  with 
which  many  anatomical  characters  prove  them  to  be 
closely  related.  Both,  moreover,  share  the  characters  of 
their  class  with  the  free-living  Turbellaria.  From  such 
as  these,  that  is  to  say,  from  forms  approximate  to  the 
present  Turbellaria,  the  Trematoda  and  Cestoda  must 
be  descended,  and  with  this  agrees  the  free  roving  phase 
which  the  larva  of  the  Fluke  (Distomum)  undergoes  as 
the  so-called  Cercaria,  and  previously  as  a  rotating 
spherical  body. 

Many  of  the  ciliated  Nematoids,  or  thread-worms, 
too, —  the  division  which  includes  the  Ascarides  among 
others, — have  in  their  infancy  a  stage  of  independent 
life,  during  which  they  cannot  be  distinguished  from 
the  infantine  forms  of  their  more  numerous  kindred, 
which  never  adopt  a  parasitic  life,  and  chiefly  inhabit 
the  sea.  The  transition  to  parasitism,  as  recapitulated 
by  ontogenesis,  was  nothing  more  than  an  extension 
to  a  new  territory  oflering  advantages  of  nutriment; 
and  on  this  point  it  is  highly  instructive  to  compare 
the  Nematodes  with  the  systematic  series  of  the  leech- 
like Suctoria  (Trematoda),  so  excellently  described 
bv  Van  Beneden.     We    here   find   all    the    transitions 


PARASITIC   CRUSTACEA. 


207 


from  independent  predatory  genera  to  others  occasion- 
ally parasitic,  and  again  from  these  to  others  which 
on  leaving  the  egg  immediately  attach  themselves  for 
life.  Here,  as  elsewhere,  parasitism  seems  an  adaptation 
to  new  habitats,  which  is  recorded  in  the  biography  of 
the  individual  with  a  reminiscence  of  the  previous  form. 
The  circumstances  of  the  parasitic  worms  are  repeated 
by  the  parasitic  Crustacea,  as,  moreover,  a  probably 
primordial  form  of  the  crab  family  is  preserved  in 
the  metamorphoses  of  several  orders  of  this  large  and 
diversified,  though  coherent  class.  The  larva,  which, 
it  may  safely  be  assumed, 
approximates  closely  to 
the  primordial  form,  was 
at  one  time  taken  for  an 
independent  genus  and  re- 
ceived the  name  of  Nau- 
plius.  Hence  a  Nauplius 
phase  is  spoken  of,  which 
obtains  especially  among 
the  lower  Crustacea,  the 
Copepoda,  parasitical  Crus- 
tacea   and   Cirripedes,   and 

the  remarkable  Rhizopoda  connected  with  them  ;  but 
is  not  wanting  in  the  highest  order,  the  decapodous 
stalk-eyed  crab.  We  shall  later  have  to  make  acquaint- 
ance with  the  so-called  curtailed  development  which 
among  the  crabs  has  been  adopted  by  the  decapods,  and 
it  was  formerly  supposed  by  all.  Were  this  actually 
the  case,  we  should  still,  by  analogy,  infer  their  connec- 
tion with  the  other  orders  repeating  the  Nauplius  phase 
in  the  course  of  their  development ;  but  it  was  a  welcome 


208 


THE   DOCTRINE   OF   DESCENT. 


discovery  of  Fritz  Miiller's  that  a  shrimp  (Peneus)  still 
begins  its  development  as  a  Nauplius  ;  whereas  all  the 
other  members  of  the  order,  as  far  as  they  are  known, 
leave  the  egg  in  the  higher  Zoea  phase  (p.  50).  As  of 
the  hundreds  of  stalk-eyed  crabs,  scarcely  a  dozen  have 
been  hitherto  examined  as  to  their  development,  it 
will  not  be  doubted  that,  with  regard  to  the  Nauplius 
phase,  some  resemble  the  Peneus  of  the  Brazilian  coast. 
But  even  were  this  case  to  prove  unique  in  the  order, 
it  would  suffice  as  a  living  w^itness  of  the  connection 


^t^' 

^c^^ 


IiG.   17.    Axolotl. 

between  the  presence  of  the  decapods  and  the  primor- 
dial crabs.  There  can  be  no  other  view  of  this  subject. 
The  Nauplius  phase  in  the  development  of  the  Peneus 
is  either  a  shining  testimony  in  favour  of  the  doctrine 
of  Descent,  or  a  senseless  paradox. 


AMPHIBIANS. 


209 


After  what  has  gone  before,  the  transformation  of  the 
Amphibians  needs  no  elucidation.  Their  predecessors 
were  water-breathers,  whose  form  and  mode  of  life  are 
more  faithfully  preserved  by  the  long-tailed  Amphibians, 
the  tritons,  and  salamanders,  than  by  the  frogs.  In 
our  tritons,  sexual  maturity  not  rarely  commences  in 
the  larval  state,  hence  in  a  phase  which  was  definitive 
in  the  progenitors  of  the  present  genera.  There  is, 
indeed,  one  species,  the  Mexican  Axolotl,  which  nor- 
mally propagates  itself  during  the  larval  phase.  Auguste 


=5r^ 


Fig,  i8.    Amblyslonia. 


Dumeril's  observation  is  highly  interesting,  that  of  the 
thousands  of  Axolotls  that  he  bred  at  Paris,  some  few 
advanced  beyond  the  grade  of  development  hitherto 
known  in  them,   i.e.  they  lost  their  gills,  changed  the 


2 TO  THE  DOCTRINE  OF  DESCENT. 

shape  of  their  bodies  not  inconsiderably,  and  from  [^ill- 
breathers,  and  aquatic  animals  became  Iimg-breathers 
and  terrestrial  animals.  It  needs  further  observation  to 
ascertain  whether  (what  is,  however,  very  improbable),  in 
their  home,  all  Axolotls,  after  having  propagated  them- 
selves in  their  larval  state,  undergo  the  metamorphosis 
into  salamander-like  animals  (Amblystoma),  or  whether 
the  transfer  to  Europe  and  the  consequent  entire  change 
of  the  circumstances  of  life  gave  the  impulse  to  a  pro- 
gressive transformation  of  these  few  individuals,  which, 
by  the  continuance  of  these  conditions,  would  in  future 
generations  extend  to  more  and  more  individuals,  and 
finally  become  the  characteristic  of  a  new  species. 

The  examples  of  Ontogenesis,  or  individual  develop- 
ment, hitherto  examined,  had  the  peculiarity  that  the 
sexual  animal  does  not  issue  directly  from  its  egg  like 
the  Phoenix  from  its  ashes,  but  had  to  pass  through 
various  forms  and  existences  in  which  the  progenitors 
of  the  species  again  become  alive  and  palpable.  We 
must  now  inquire  how  this  development  is  related  to  that 
form  of  reproduction  which  the  systematizers,  completely 
in  accordance  with  the  facts,  yet  without  any  corre- 
sponding meaning,  have  termed  "  direct  development," 
or  "development  without  heterogenesis  or  metamor- 
phosis? "  The  ciliated  embryos  of  many  Medusae  are  not 
converted  into  polype-like  intermediate  forms,  but  pass 
directly  into  Medusae.  The  greater  number  of  higher 
crabs  do  not  leave  the  egg  as  Nauplia,  but  as  more  or 
less  perfect  decapods.  The  bird,  the  mammal,  and 
man  are  all  at  birth  "similar  to  their  parents."  Con- 
sidering that  the  processes  of  heterogenesis  are  in  them- 
selves by  no  means  advantageous  to  or  "in  harmony 


DIRECT   DEVELOPMENT.  211 

with  design** — we  have  only  to  remember  the  fate  of 
the  tapeworm's  eggs — that  by  the  larval  state  the 
period  of  infancy  and  weakness  is  prolonged,  and  the 
period  of  maturity  and  efticient  care  for  the  continuance 
of  the  species  delayed,  it  follows  that  curtailments  and 
reductions,  consequent  on  adaptation  have,  as  advan- 
.  tageous  modifications,  a  prospect  of  perpetuation.  As 
in  Amphibians  the  prolongation  of  the  larval  phase  may 
be  effected  by  natural  circumstances  and  artificial  ex- 
periments, so  in  like  manner  a  compression  of  the  phases 
of  transformation,  and  a  general  curtailment  of  the 
metamorphosis  is  imaginable.  In  the  class  of  Amphi- 
bians we  have,  in  fact,  several  examples  of  curtailed  and 
modified  metamorphosis  which  bridge  over  the  apparent 
chasm  between  development  with  and  without  transfor- 
mation, and  render  direct  development  comprehensible 
as  being  gradually  acquired.  Amphibians  will  endea- 
vour to  extend  themselves  wherever  they  are  invited  by  a 
sufficient  supply  of  insects,  and  the  black  salamander  of 
the  mountains  (Salamandra  atra)  has  even  overcome  the 
impediment  which  might  have  been  deemed  insurmount- 
able, the  absence  of  water  for  its  larvae.  It  does  not  lay 
its  eggs  like  its  congeners,  but  only  two  are  received 
into  the  oviduct,  and  the  fluids  secreted  from  its  walls 
replace  the  marsh  to  them  and  to  the  larvae  which 
emerge  from  them.  Here,  and  not  when  separated  from 
the  parent,  do  the  gills  make  their  appearance,  while  the 
other  eggs,  gradually  following,  are  devoured  by  the 
hungry  larvae.  The  metamorphosis  of  the  black  sala- 
mander, which  has  lately  been  the  subject  of  Fr. 
Marie  Chauvin's  remarkable  experiments,  can  be  effected 
after  exclusion,  and  observation  places  it  beyond  a 
15 


212  •     THE   DOCTRINE   OF  DESCENT. 

doubt  that  this  is  an  instance  of  adaptation  to  unusual 
conditions.  If  the  mode  of  life  of  the  marsupial  frog, 
which  carries  its  young  in  a  membranous  fold  of  the 
back,  and  the  Surinam  toad,  of  which  the  larvae  live 
singly  in  the  chambers  of  a  kind  of  honeycomb  on  the 
back,  were  better  known  than  they  are,  we  should 
assuredly  arrive  at  the  same  results  as  with  the  black 
salamander.  In  the  absence  of  ether  knowledge,  the 
observations  of  M.  Bavey,  Marine  Pharmaceutist  at 
Guadaloupe,  first  published  in  1873,  are  of  the  highest 
importance.®*  A  frog  of  those  parts  (Hylodon  Martini- 
censis)  goes  through  its  whole  metamorphosis  in  the 
egg.  In  the  egg  it  has  gills  and  tail ;  and  from  the  brief 
remark  that  the  island  contains  only  rapid  running 
.streams,  and  nowhere  stagnant  waters  or  marshes,  it 
appears  that  this  is  also  a  case  in  which  adaptation 
modifies  and  curtails  development. 

If,  after  this  introduction,  we  now  examine  the  so- 
called  direct  development  with  more  attention,  it  may 
in  every  way  be  compared  to  the  metamorphosis  of 
the  Hylodes  of  Guadaloupe.  Direct  development  is 
a  transformation  in  the  ovum  ;  and  in  the  cases  in 
which  it  occurs,  the  phases  of  embryonic  development 
are  repetitions,  more  or  less  distinct,  of  the  historic 
development  of  the  family.  We  will  only  particularize 
in  the  embryonic  life  of  the  Vertebrata  (in  v/hich 
metamorphosis  does  not  take  place),  some  phases  that 
are  stages  of  curtailed  transformation,  and  recapitu- 
late the  permanent  condition  of  their  progenitors.  It 
has  been  repeatedly  mentioned  that  in  all  vertebrate 
animals,  the  vertebral  column  is  first  laid  out  as  an 
unsegmented  cord  and  an  unsegmented  sheath  for  the 


DEVELOPMENT  OF  AMMONITES.  21 3 

spinal  cord.  This  is  the  permanent  state  of  the  lower 
fishes.  In  the  higher  Vertebrata  also,  the  brain  at 
first  consists  of  vesicles,  lying  one  behind  the  other, 
which  is  the  persistent  form  of  the  lower  groups.  The 
embryonic  heart  of  mammals  and  birds  begins  in  the 
form  of  a  tube,  and  subsequently  acquires  the  com- 
munications between  the  chambers,  which  in  the 
reptiles  never  close.  In  the  Amphibians,  the'  branchial 
arches  really  bear  gills  during  the  larval  state.  They 
are  not  wanting  in  the  embryos  of  reptiles,  birds,  and 
mammals,  any  more  than  the  fissures  through  which,  in 
fish  and  the  ian^ae  of  Amphibians,  the  water  passes  ofif 
after  being  inhaled.  Must  we  again  set  forth  the  only 
possible  explanation  of  these  facts  ? 

Before  referring  to  the  phenomena  which  testify  the 
emanation  of  families  from  a  common  root,  we  will  cite 
one  of  the  most  important  evidences  of  recent  times, 
which  traces  the  genesis  of  species  through  a  great 
geological  period,  and  exhibits  in  detail  the  relations 
of  the  development  of  the  individuals  to  that  of  the 
species,  genus,  and  family.  We  mean  L.  Wurten- 
berger's  contribution  to  the  geological  evidence  of  the 
Darwinian  theor}%  to  which  we  have  already  appealed 
(p.  97).  It  relates  to  the  two  families  of  Ammonites,  the 
Planulata  and  Armata  ;  of  which,  according  to  Wiirten- 
berger's  researches,  the  latter  are  developed  from  the 
former,  as  the  ribs  of  the  Planulata  gradually  pass  into 
the  spines  of  the  Armata.  Of  special  interest  to  us  are 
the  following  passages  of  the  preliminary  communication 
on  the  discoveries  obtained  from  thousands  of  specimens, 
and  which  will  probably  not  be  made  public,  with  all  the 
vouchers,  for  some  ye^rs  to  come.     "  It  gave  me  parti- 


214 


THE   DOCTRINE   OF   DESCENT. 


cular  pleasure,"  says  Wiirtenberger,  "  when,  after  divers 
careful  comparative  studies,  I  at  last  detected  an  inter- 
esting and  simple  conformity  to  law  in  the  variations  of 
the  Ammonites.  Namely,  on  the  first  appearance  of  a 
modification  which  subsequently  attains  essential  import- 
ance in  an  entire  group,  it  is  only  slightly  indicated  on  a 
portion  of  the  last  convolution.  Towards  more  recent 
deposits,  this  modification  is  more  and  more  plainly 
shown,  and  then  advances,  following  the  spiral  course  of 


Fig.  19.    Animoiiites  Humphresianus.    A  form  analogous  to  the  Planulata. 

the  shell ;  that  is  to  say,  it  gradually  takes  possession 
of  the  central  turns  also,  as  we  trace  the  forms  to  higher 
strata.  This  reproduction  in  younger  stages  of  life  of 
modifications  first  occurring  at  a  more  advanced  age, 
makes  but  slow  progress,  so  that  we  see  the  older  forms 
repeated  with  great  persistency  in  the  central  turns. 
Frequently  a  modification  of  this  sort  has  taken  posses- 
sion of  only  a  small  part  of  the  convolutions,  when  a 
new  one  already  appears  at  the  outside,  and  follows  the 


DEVELOPMENT  OF  AMMONITES.  215 

first.  Thus  searching  through  the  strata  from  below 
upwards,  we  see  modification  after  modification  begin- 
ning at  the  outer  part  of  the  Ammonites,  and  advancing 
towards  the  centre  of  the  discs.  The  innermost  convo- 
lutions often  resist  these  innovations  with  great  persis- 
tency, so  that  we  usually  find  upon  their  surface  several 
of  these  states  of  development  in  close  juxta-position, 
as  the  shell  of  the  individual  Ammonite  begins  with 
the  old  morphological  type,  and  then  adopts  the  modifi- 
cations in  the  same  order  in  which  they  follow  in  vast 
periods  in  the  geological  development  of  the  groups  con- 
cerned." 

"  The  Ammonites,"  he  says  moreover,  "  thus  obtain 
at  an  advanced  and  maturer  age — only  when  they  have 
gone  through  the  development  inherited  from  their 
parents,  and  as  much  as  possible  in  the  same  manner  as 
tneir  parents — the  power  of  modifying  themselves  in  a 
new  direction,  that  is  to  say,  of  adapting  themselves  to 
new  conditions ;  yet  these  modifications  may  then  be 
transmitted  to  the  offspring,  so  as  to  appear  in  each 
subsequent  generation  a  trifle  earlier,  until  this  phase  of 
development  in  its  turn  characterizes  the  greater  portion 
of  the  period  of  growth.  But  this  last  and  longest 
phase  of  development  scarcely  ever  suffers  itself  to  be 
supplanted  by  new  ones,  formed  in  like  manner;  heredity 
operates  so  powerfully,  that  a  period  of  development 
thus  once  predominant,  is  repeated  in  the  infancy  of  the 
Ammonites,  even  though  but  slightly  indicated.  Hence 
in  an  individual  Ammonite  from  a  recent  stratum,  the 
periods  of  development  compressed  and  forced  back 
upon  the  innermost  convolutions,  must  appear  in  the 
same  succession   in  which  they  wrested  the  dcminion 


2l6 


THE  DOCTRINE   OF  DESCENT. 


from  one  another.  It  is  extremely  interesting  to  study 
the  development  of  the  Inflata  of  the  upper  white  Jura 
(which  follow  the  Ammonites  liparus,  whose  externally 
visible  convolutions  display  only  one  row  of  spines),  care- 
fully breaking  off  convolution  by  convolution.  Towards 
the  middle  there  is  a  region  in  which  there  are  always 
two  rows  of  spines  ;. nearer  the  centre  the  innermost  row 
disappears ;  soon  afterwards  the  outer  one  also  ;  and  the 
nucleus,  some  millimetres  in  diameter,  now  appears  for 
about  half  a  turn  as  a  Planulatum,  with  distinct  ribs, 
which,  towards  the  beginning,  likewise  disappear.  Thus 
even  the  Planulate  ribs,  which  prevailed  among  the 
Liassic  ancestors  of  these  Inflata,  and  were  supplanted  by 
the  spines  as  early  as  in  the  brown  Jura,  still  distinguish 
these  later  and  essentially  modified  descendants  during 
a  short  period  of  their  youth." 

Wiirtenberger  further  shows  how 
these  relations  can  be  simply  ex- 
plained by  the  Darwinian  theory 
alone  ;  *'  without  it  we  should  have 
only  an  extraordinary  problem." 

It  was  natural  to  test  the  applica- 
bility of  the  theory  of  selection  also 
on  the  forms  allied  to  the  Ammonites, 
such  as  the  Ancyloceras;  namely,  the 
genera  in  which  the  convolutions  do 
not  touch  and  partially  conceal  one 
another,  as  in  genuine  Ammonites, 
and  which,  as  late  comers  and  side 
shoots  of  the  group,  seemed  des- 
FiG.  20.  Ancyloceras.  tincd  to  dccay.  Sclcctlon  aud  dccay  .-^ 
Wiirtenberger  shows  how  the  abandonment  of  contact 


FORMS  ALLIED   TO  AMMONITES. 


217 


in  the  convolutions  was  to  the  spinous  Ammonites  an 
advantage  which  would  be  established  by  selection.  If 
other  palaeontologists  consider  the  fluctuations  of  form 
accompanying  the  relaxation  of  the  closed  spiral  as 
evincing  the  decline  of  the  group,  no  contradiction 
seems  to  be  implied,  for  what  was  originally  used  as  an 
advantage  by  natural  selection,  proved  injurious  in  its 
consequences. 

As  we  have  seen,  the  earliest  states  are  obliterated  to 


such  a  degree  by  curtailment  of  development  that  the 
indication  of  the  nature  of  the  progenitors  continually 
diminishes.  But  our  theory  necessarily  leads  to  the 
conviction  that  the  families  within  which  we  have  as 
yet  been  able  to  compare  Ontogenesis  with  Philogenesis, 


2l8  THE  DOCTRINE  OF  DESCENT. 

constantly  approximate  in  their  origin,  and  vindicate  the 
expectation  that  at  least  here  and  there,  in  the  indi- 
vidual development  of  single  representatives  of  the 
various  families,  witnesses  of  their  common  derivation 
should  come  to  light.  This  likewise  occurs,  and  to 
such  a  degree  that  in  the  earliest  larval  stages  a 
link  is  established  between  the  lowest  and  the  highest 
animals.  If  a  number  of  groups  of  the  lowest  living 
beings,  in  which  the  various  vital  functions  of  nutrition, 
irritability,  motion,  and  reproduction  are  supplied  by 
amorphous  protoplasm, — if  these  be  separated,  as  by 
Haeckel,  into  a  neutral  kingdom,  owing  to  the  absence 
of  sexual  reproduction,  we  must  likewise  agree  with 
him  in  attributing  to  the  Spongiada^  ranking  next  to 
the  Protista,  the  namo  of  animals,  on  account  of  their 
sexual  propagation  and  the  nature  of  their  embryonic 
development  and  first  larval  phases. 

Haeckel  has  bestowed  on  one  larval  stage  of  the 
calcareous  sponges  the  title  of  Gastrula,  wherein  the 
animal  represents  a  sac,  or,  in  other  words,  a  stomach 
provided  with  a  mouth-like  orifice.  The  walls  are 
formed  of  two  rows  of  cells,  the  outer  one  consisting  of 
ciliated  cells  ;  that  is  to  say,  each  cell  is  furnished  with 
a  long  filament.  At  the  orifice  of  the  sac,  the  outer  row 
merges  into  the  inner  one,  and  from  these  two  mem- 
branes the  body  of  the  sponge  is  constructed  in  a  definite 
manner.  Now,  if  this  Gastrula  larva  reappears  in  the 
Ccelenterata,  Polypes,  and  Medusae,  in  which  the  gradual 
development  from  the  two  membranes,  the  entoderm 
and  ectoderm,  into  the  most  complex  forms  has  long 
been  known  ;  and  if,  as  Haeckel  has  further  shown,  the 
osculum,  or  larger  opening  of  the  spongiadae  may  be 


GERMINAL  MEMBRANES.  2ig 

closely  compared  with  the  mouth  of  the  polype  and 
medusa,  and  the  great  central  cavity  of  the  sponge  with 
the  stomach  of  the  others,  of  the  canal  system  with 
the  canals  and  cavities  of  the  Ccelenterata, — then,  in 
combination  with  the  host  of  other  facts,  implying  and 
supporting  the  doctrine  of  Descent,  the  inference  is 
•jievitable  that  in  the  Gastrula  we  have  a  testimony 
of  the  consanguinity  of  the  Spongiadre  and  Ccelen- 
terata. But  this  Gastrula  reappears  in  the  Holothuria  ; 
hence  in  the  Echinoderms,  in  the  Sagitta,  in  the 
Ascidians,  which  will  be  more  narrowly  examined  in 
the  pedigree  of  the  Vertebrata,  and  finally  in  the 
Lancelet;  and  we,  therefore,  hold  ourselves  justified 
in  regarding  this  coincidence  of  the  earliest  states  of 
development  in  different  families,  as  the  remnant  of 
the  common  root,  which  in  other  families,  as  in  the 
Articulata,  for  example,  has  been  lost  in  the  cur- 
tailment of  development.  The  significance  of  the 
"  germinal  membranes "  in  the  Vertebrata  was  recog- 
nized even  by  Pander,  and  in  the  suggestive  works  of 
V.  Baer  ;  the  extension  and  application  of  this  observa- 
tion to  the  whole  animal  kingdom,  for  which  we  are 
especially  indebted  to  Kowalewsky,  marks  one  of  the 
greatest  advances  in  the  science  of  comparative  de- 
velopment. 

1  he  reader  unacquainted  with  the  detailed  researches 
of  our  science,  has  already  been  called  upon  to  observe 
that  there  are  opponents  of  the  theory  of  selection,  such 
as  Owen,  who  nevertheless  accept  the  doctrine  of  Descent 
as  incontestable.  Even  rejecting  natural  selection,  the 
parallelism  of  Ontogenesis  with  Phylogenesis  may  also 
be  brought  into  the  natural  connection   maintained  by 


220  THE  DOCTRINE  OF  DESCENT. 

US,  on  the  assumption  of  an  unnatural  or  supernatural 
guidance  which  converts  this  apparently  natural  unity 
into  a  miracle.  Quite  recently,  A.  Braun  has  pointed  out 
the  accordance  of  the  botanical  system,  and  therewith 
of  palaeontological  succession,  with  the  development  of 
the  individual  plant,  when  he  says  :®^ — "  In  the  further 
elaboration  of  the  natural  system,  the  gradation  of  the 
vegetal  kingdom,  and,  at  the  same  time,  the  relation  of 
the  system  to  the  history  of  development,  becomes  more 
and  more  spontaneously  and  incontrovertibly  manifest. 
The  Acotyledons  are  verified  as  Cryptogams,  as  they 
were  already  considered  by  the  old  botanists  of  pre- 
Linnaean  times,  and  their  relation  to  the  Phaenogams  is 
thus  more  clearly  pronounced.  The  Cryptogams  are 
separated  into  two  essentially  different  divisions, 
in  which  gradation  is  likewise  distinctly  pronounced 
(cellular  and  vascular  Cryptogams,  Thallophytes  and 
Kormophytes) ;  between  the  perfect  Phaenogams  and 
the  Cryptogams  an  intermediate  grade  has  been  shown, 
that  of  the  Gymnosperms.  But  most  important  of  all 
is  the  circumstance  that  the  four  chief  grades  ascer- 
tained in  the  vegetal  kingdom  accurately  correspond 
with  the  grades  of  development  occurring  in  the  indi- 
viduals of  all  the  higher  plants  ; — the  germ,  the  vegeta- 
tive stem,  the  blossom  and  the  fruit."  But  why  this 
parallelism  is  to  be  most  important  of  all,  if  it  is  not 
to  lead  us  to  the  knowledge  of  true  causality,  is  beyond 
our  comprehension.  We  can  well  imagine  that  the 
"inherent  causes"  and  the  "Principle  of  Perfection"  may 
be  welcomed  as  the  refug'mm  ignorantice,  but  not  that 
they  can  really  satisfy  inquiry.  For  our  own  standpoint, 
the  accordance  of. the  results  of  botanical  investigation 


THE   BEGINNING  OF  LIFE.  221 

must  be  extremely  important,  but  it  is  for  the  palpable 
reason  that  the  theory  thereby  gains  the  support  and 
corroboration  of  another  great  series  of  facts. 

If  the  accordance  of  the  evolution  of  families  has 
once  been  followed  up  to  the  Gastrula,  we  shall  no^ 
pause  there,  but  must  regard  the  similarity  of  the  sperm 
corpuscules  and  germ  cells  from  the  Spongiadae  to  the 
Vertebrata  as  a  primordial  common  property,  con- 
necting the  animal  and  vegetal  world  ;  and  prior  to  the 
acquisition  of  which,  only  those  modes  of  reproduction 
took  place  which  have  been  maintained  among  Protista 
and  in  heterogenesis. 

As  the  common  basis  of  sexual  reproduction  in  the 
various  families  argues  a  common  origin,  asexual  re- 
production, directly  connected  as  we  have  seen  it  to 
be  with  sexual  propagation,  by  means  of  unfecundated 
eggs  and  germs,  leads  us  constantly  further  towards  the 
beginning  of  life.  But  the  cell  furnished  with  a  nucleus 
and  sheath  is  inseparable  from  the  protoplasmic  cor- 
puscule  devoid  of  nucleus  or  sheath,  on  the  growth  and 
fission  of  which  rests  the  reproduction  of  the  lowest 
living  beings. 

Their  origin  from  inorganic  matter,  as  we  have  set 
forth  above,  is  a  postulate  of  sound  human  under- 
standing. To  this  beginning  we  are  led,  not,  as  the 
opponents  of  the  doctrine  of  Descent  are  wont  to  say, 
by  a  dogmatic  after-philosophy,  but  by  the  unpre- 
judiced consideration  and  computation  cf  the  facts  of 
individual  development.*^'' 


i22  THE  DOCTRINE  OF  DESCENT. 


The  Geographical  Distribution  of  Animals  in  the  light  of  the  Doctrine  ol 
Derivation. 

Although  ever  since  the  century  of  the  great  geo- 
graphical discoveries,  material  has  been  accumulating 
for  a  geography  of  plants  and  animals,  the  foundations 
of  scientific  botanical  geography  (apart  from  George 
Forster's  observations)  were  first  contained  in  Hum- 
boldt's celebrated  "Ideas  on  the  Physiognomy  of  Plants" 
(Ideen  zu  einer  Physiognomik  der  Gewachse).  It  is  the 
first  description  of  vegetal  forms,  comprising  the  entire 
area  of  the  earth,  and  the  manner  in  which,  singly  or 
combined,  they  lend  a  characteristic  impress  to  the 
landscape  of  their  region  of  distribution,  and  again  on 
their  side  harmonize  with  the  other  factors  of  the  scene. 
The  celebrated  founder  of  Climatology,  who  circled  the 
terrestrial  globe  with  lines  of  equal  temperature,  of 
equal  inclination  and  declination  of  the  magnetic  needle, 
and  divided  it  into  dry  and  rainy  zones,  knew  better 
than  any  of  his  contemporaries  that  the  animal  and 
vegetal  world  depended  on  all  these  factors.  Yet 
neither  he  nor  his  followers,  before  Darwin,  rose  higher 
than  the  description  of  Nature,  which  had  already 
checked  Buffon  in  his  grand  picture  of  Nature,  "Les 
rpoques  de  la  Nature." 
A  natural   result  of  the  extraordinary  extension  of 


VICARIOUS   FORMS.  223 

the  geographical  horizon  and  the  profundity  of  special 
research  was  the  more  careful  ascertainment  of  the 
regions  of  distribution  of  animal  and  vegetal  families, 
and  of  their  more  prominent  species,  in  which,  as  we 
have  already  said,  either  no  questions  were  asked  as  to 
the  causes  of  distribution,  or  the  matter  was  facilitated, 
as  by  Louis  Agassiz,  who  did  not,  like  Linnaeus,  derive 
each  species  from  a  pair,  but  supposed  them  to  be 
created  in  suitable  numbers  of  individuals  in  their  own 
regions  of  distribution.  It  cannot  be  expected  that 
any  solution  was  hereby  given  to  the  questions  which 
now  force  themselves  upon  us,  such  as  why,  under  like 
natural  conditions,  like  species  are  not  always  to  be 
found,  and  conversely  ?  Why  very  similar  species  fre- 
quently appear  under  external  conditions  entirely  dis- 
similar ?  What  is  to  be  thought  of  the  mutual  relations 
of  the  so-called  vicarious  forms  ?  &c. 

As  Riitimeyer  has  recently  observed,  in  his  excellent 
treatise  "  On  the  Derivation  of  the  Animal  World  of 
Switzerland"  ("Ueber  die  Herkunft  der  schweizerischen 
Thierwelt "  ^®),  Buffon  had  already  remarked  the  repe- 
tition of  the  African  in  the  American  fauna  ;  how,  for 
example,  the  lama  is  a  juvenescent  and  feeble  copy  of  the 
camel ;  and  how  the  puma  of  the  New  represents  the 
lion  of  the  Old  World.  Still,  by  the  mere  v/ord  "  repre- 
sentative "  or  "  vicarious  form  "  nothing  is  gained,  and 
a  true  apprehension  of  these  facts  is  obtained  singly  and 
solely  if  we  meet  the  inquiry  with  the  assumption  that 
camel  and  lama,  puma  and  lion,  are  of  common  deriva- 
tion, and  that  their  diverse  development  was  in  the 
lapse  of  time  favoured  and  determined  by  the  separa- 
tion of  the  habitats  of  their  progenitors. 


224  THE  DOCTRINE  OF  DESCENT.   - 

Another  example  of  so-called  vicarious  or  "analogous" 
species,  affording  an  easier  basis  for  induction,  is  provided 
by  the  comparison  of  the  snails  of  Southern  Europe, 
and  especially  of  Spain,  with  those  of  North  Africa,  on 
which  we  are  indebted  to  Bourguignat  for  some  excel- 
lent observations.  In  accordance  with  other  botanical 
and  zoological  facts,  he  has  established  that  the  shell 
fauna  of  Spain  and  North  Africa  forms  a  whole,  so  that 
the  Algierian  snails  appear  a  mere  appendage  to  those 
of  Southern  Europe,  nothwithstanding  the  separation 
by  the  Straits  of  Gibraltar.  Now  it  is  proved  that,  in 
geologically  recent  times,  this  region  of  North  Africa 
was  in  fact  a  peninsula  of  Spain,  and  that  its  union 
with  Africa  was  effected  on  the  north  by  the  rupture 
of  the  Straits  of  Gibraltar,  and  on  the  south  by  an 
upheaval  to  which  the  Sahara  owes  its  existence.  The 
shores  of  the  former  Sea  of  Sahara  are  still  marked  by 
the  shells  of  the  same  snails  that  live  on  the  shores  of 
the  Mediterranean.  But  all  North  African  species  are 
not  identical  with  those  of  Spain ;  of  many  African 
sorts,  only  "  analogous  "  species  are  found  on  our  side. 
Now  if  certain  Spanish  species  do  not  themselves  occur 
in  Africa,  but  are  yet  replaced  by  very  similar  forms, 
our  standpoint  at  once  connects  with  the  otherwise 
unmeaning  word  "  analogous  "  species  the  idea  of  the 
common  derivation  of  the  forms  replacing  one  another, 
and  of  the  local  variations  superinduced  by  isolation 
and  altered  conditions. 

A  severe  test  is  applied  to  those  who  believe  that 
species  were  separately  created,  by  the  air-breathing 
land  snails  (pulmo-gasteropoda),  when  it  is  seen  that  in 
isolated   islands   and   island   groups  these  earth-bound 


ANALOGOUS  FORMS.  22$ 

animals,  migrating  with  so  much  difficulty,  have  attained 
un  extraordinary  diversity.  In  the  Madeira  Islands, 
134  species  of  pulmo-gasteropoda  were  reckoned  about 
ten  years  ago,  of  which  only  21  were  to  be  found  in 
the  Africo-European  fauna.  These  and  the  113  other 
species  are  mostly  confined  to  narrow  districts  and  single 
valleys.  Are  we  to  suppose  that  the  113  species  for 
Madeira,  and  the  21  species  for  Madeira  and  Africa 
with  Europe,  were  each  separately  created  ?  Must  we 
not  much  rather  infer  that  a  connection  at  one  time 
existed  between  Europe  and  the  present  island  group 
of  Madeira,  and  that  these  21  species  remained 
what  they  were  before  the  separation ;  while  from 
unknown  species  still  appearing  in  analogous  forms 
upon  the  continent  emanated  the  remarkable  profusion 
of  new  species  ?  They,  and  their  comrades  on  other 
isolated  islands,  were  spared  a  conflict  many  sided, 
and  they  doubtless  afford  a  favourable  example  of 
Wagner's  law  of  migration,  as  with  the  difficulties  of 
locomotion,  and  the  improbability  of  a  large  subsequent 
arrival,  the  secluded  individuals,  under  even  slightly 
different  influences,  had  had  a  prospect  of  diverging 
from  the  parent  species. 

The  unscientific  opinion,  that  under  like,  or  nearly 
like,,  external  conditions,  like  or  similar  organisms 
were  created  in  great  numbers,  receives  a  severe  blow 
by  the  perception  that  the  direct  reverse  has  frequently 
occurred.  Why  has  America  no  horses  in  the  present 
era,  although  it  is  proved  that  the  horses  introduced, 
thrive  capitally .?  It  is  not  necessary  for  us  to  explain 
why  the  fossil  horses  which  existed  in  America,  as  well 
as  in  the  Eastern  hemisphere,  became  extinct  without 


226  THE  DOCTRINE  OF  DESCENT. 

leaving  any  progeny — we  do  not  know  the  cause, 
though  we  may  yet  be  able  to  fathom  it ;  but  in  this 
and  all  similar  cases  the  adherents  of  the  doctrine  ot 
Creation  must  confess  the  inadequacy  of  their  theory 
of  belief. 

Our  exposition  has  shown  that  the  species  now  extant 
are  the  progeny  of  organisms  previously  existing ;  the 
present  apportionment  on  the  earth  is  therefore  a 
consequence  of  the  distribution  of  the  progenitors  of 
the  present  organisms,  and  of  the  manifold  displace- 
ments of  land  and  water  by  which  they  were  indirectly 
or  directly  affected.  We  cannot  hope  ever  to  picture 
to  ourselves  a  faithful  representation  of  the  perpetual 
transformations  of  the  surface  of  the  earth.  Only,  if 
this  could  be  accomplished,  and  if  we,  moreover,  had  an 
accurate  register  of  the  animals  at  each  period  inhabiting 
the  former  islands,  continents,  and  oceans — only  then 
could  the  distribution  of  the  present  organisms  be 
thoroughly  fathomed  and  established.  But  in  thus  ac- 
knowledging the  incompleteness  of  our  statistical  means, 
we  are  at  least  able  to  lay  down  with  certainty  the  course 
of  inquiry.  We  must,  in  the  first  place,  proceed  in  the 
method  of  the  older  vegetal  and  animal  geography 
to  ascertain  the  natural  limits  and  regions  of  distribu- 
tion I  and,  secondly,  to  collate  these  facts  with  the  facts 
of  the  distribution  of  the  former  progenitors  of  the 
present  animate  world  as  it  was  determined  by  the 
geological  conditions  of  those  times.  It  is  needless  to 
say  that  Darwin  has  furnished  the  outlines  for  this  work 
also.  But  among  his  followers  two  are  specially  worthy 
of  distinction  :  Wallace,  with  his  researches  on  the 
Malay  Archipelago,'"  abounding  in  subtle  observation  ; 


DISTRIBUTION   OF  ANIMALS.  227 

and  Riitlmeyer,  in  his  treatise  already  cited.  In  what 
follov/s  we  may  essentially  adhere  to  the  latter. 

Our  knowledge  of  the  regions  of  distribution  of  the 
animal  world  is  still  extraordinarily  deficient.  What  do 
we  know,  for  instance,  of  the  occurrence  of  marine  ani- 
mals ?  Few  years  only  have  elapsed  since  the  depths  ot 
the  sea  were  rendered  accessible  to  research,  and  the 
result  has  almost  entirely  upset  our  earlier  notions  of 
the  geological  significance  of  the  sea-bottom  and  its 
habitability.  After  the  strong  impulse  given  by  Maury 
to  the  investigation  of  the  physical  condition  of  the  sea, 
we  are  now  occupied  in  ascertaining  the  submarine  tem- 
peratures and  currents,  the  constitution  of  the  sea-bottom, 
the  occurrence  of  deep-sea  organisms,  and  the  conditions 
of  their  existence.  We  are  therefore  just  beginning  to 
collect  the  material  for  a  future  geography  of  marine 
organisms.  Among  terrestrial  animals,  certain  groups 
of  which  the  actual  distribution  can  be  defined,  are  use- 
less for  our  general  purpose. 

Butterflies,  for  instance,  which  are  an  easy  prey  to 
currents  of  air,  defy  geological  barriers,  and,  above  all, 
that  important  partition  which  from  the  tertiary  era 
has  been  erected,  or  rather  excavated  in  the  bottom  of 
the  sea,  between  Australia  and  India."  It  is  the  same 
with  bats,  and  also  with  migratory,  predatory,  and 
aquatic  birds;  while,  as  Wallace  shows,  the  other  orders 
of  this  class  are  in  tropical  regions  very  reliable  and 
stable  inhabitants  of  their  often  limited  districts,  seem- 
ingly suggestive  of  migration.  Exclusive  of  these, 
there  remains  therefore  little  more  than  the  Mammalia, 
whose  extraction  may  be  inferred  with  certainty  from 
a  comparison  of  their  present  cantonments  (Cantonirung), 
16 


228  THE   DOCTRINE   OF   DESCENT. 

— an  expression  which  we  borrow  from  Rlitimcyer, — 
with  the  encampments  of  their  former  kindred,  whence 
are  derived  general  points  of  view  as  to  the  causes  of 
the  present  geographical  apportionment  of  organisms. 

If  in  the  preliminary  establishment  of  facts  we  there- 
fore confine  ourselves  to  the  Mammalia,  exclusive  of 
whales  and  bats,  a  superficial  survey  is  enough  to  show 
that  not  only  single  species,  but  families  also,  have  each 
a  certain  region  of  greatest  density  of  occurrence,  a 
focus  of  distribution,  and  that  from  thence  radiations 
have  taken  place  according  to  the  convenience  and  fit- 
ness of  the  territory.  Lion  and  tiger,  elephant  and 
camel,  range  over  a  definite  area ;  the  monkeys  of  the 
New  World  differ  from  those  of  the  Old  World  not  only 
geographically,  but  also  in  family  characteristics.  Mar- 
supials are  chiefly  concentrated  in  Australia  ;  sloths  and 
armadilloes  in  South  America.  And  these  examples, 
easy  to  multiply,  indicate  how  individuals  of  widely 
dispersed  species,  and  the  species  themselves,  emanated 
from  single  points  of  the  earth's  surface  and  flowed  over 
the  territory  of  distribution  now  occupied.  When  to 
this  observation  is  added  the  other,  that  in  past  eras 
also  the  same  groups  had  the  same  centres  of  distri- 
bution,— for  instance,  Brazil  not  only  harbours  sloths 
and  armadilloes  now,  but  was  once  peopled  by  more 
numerous  and  partly  colossal  species  of  these  families, 
and  Australia  has  furnished  the  most  numerous  and 
important  fossil  remains  of  Marsupials, — the  cogniz- 
ance of  this  persistent  localization  becomes  very  signi- 
ficant, and  we  account  for  the  "repetition"  of  these 
forms  by  derivation. 

Now  if  the  centres  of  distribution,  at  the  first  glance 


ORIGIN  OF  ISLANDS.  229 

extremely  numerous,  can  be  brought  into  closer  union 
and  reduced  to  the  smallest  number  possible,  as  by  our 
theory  the  Mammalia  have  but  one  point  of  derivation, 
and  if  we  can  herewith  harmonize  the  geological  succes- 
sion of  the  organisms  examined,  or,  in  other  words,  har- 
monize the  horizontal  distribution  with  the  vertical  or 
historical  sequence,  animal  geography  will  then  approach 
the  solution  of  its  task.  Wallace  and  Riitimeyer's  works 
are  therefore  an  important  advance,  as  the  former  has 
given  detailed  evidence  that  the  fauna  of  the  complex 
and  extensive  Australio-Indian  Archipelago  is  by  no 
means  self-dependent,  but  consists  merely  of  offshoots 
of  the  continents  ;  and  the  latter,  in  a  grand  survey  of 
the  entire  surface  of  the  earth,  has  reduced  the  centres 
of  distribution  to  the  simplest  proportions  as  yet 
possible. 

The  comparison  of  insular  and  continental  faunas  is 
naturally  of  great  interest.  For  should  it  appear  that, 
with  respect  to  the  animal  world,  islands  are  one  and  all 
mere  appendages  of  the  continents,  the  problem  would 
at  once  be  vastly  simplified.  If  we  follow  Peschel's 
luminous  exposition  of  the  origin  of  islands,^"*  we  have 
first  to  deal  with  the  fragments  of  continents.  A  great 
number  of  islands,  such  as  Great  Britain  and  the  great 
Asiatic  islands,  may  be  recognized  at  once  as  fragments 
of  still  existing  continents.  On  the  other  hand,  Mada- 
gascar and  the  Seychelles  are  not,  as  might  be  con- 
jectured, a  segment  of  Africa,  but  the  remnant  of  a 
former  continent  very  peculiar  in  its  flora  and  fauna. 
Other  islands  originate  either  from  submarine  volcanoes 
or  from  corals,  and  in  the  latter  case  the  structure  is 
founded  on  sinking  land.     It  naturally  follows  that  on 


230  THE  DOCTRINE  OF  DESCENT. 

volcanic  and  coral  islands  only  such  animals  will  be 
encountered  as  reached  them  by  swimming  or  flying. 
The  presence  of  Mammals  pre-supposes  human  agency 
or  extraordinary  accidents.  The  older  the  islands,  the 
richer  are  they  in  organisms.  Islands  detached  from 
continents  will,  on  the  contrary,  be  rich  in  proportion 
as  they  are  recent,  of  which  Great  Britain  bears  witness. 
The  more  divergent  is  their  fauna,  the  longer  must  be 
the  time  which  has  elapsed  since  their  separation.  Thus, 
for  instance,  we  may  view  the  relations  of  Tasmania 
and  Australia  ;  and  if  New  Zealand  was  ever  connected 
with  the  old  Australian  continent,  the  separation  occur- 
red at  an  epoch  so  remote  that  it  throws  no  light  upon 
the  physiognomy  of  the  animal  world  of  New  Zealand, 
and  vice  versa. 

In  the  account  of  his  travels  in  the  Malay  Archipelago, 
Wallace  has  given  a  pattern  of  animal-geographical 
research.  Years  before,  G.  Windsor  Earl  had  pointed 
out  that  the  great  islands  of  Sumatra,  Borneo,  and  Java, 
are  connected  with  the  Asiatic  continent  by  a  shallower 
sea  ;  while  a  similar  shallow  sea  assigns  New  Guinea 
and  several  adjacent  islands  to  Australia,  with  which 
they  have  a  common  characteristic  in  the  Marsupials. 
Wallace  has  defined  this  partition  more  minutely  with 
a  line  marked  by  a  deeper  submergence  of  the  sea- 
bottom.  It  is  drawn  below  the  Philippine  Islands, 
and,  having  Celebes  to  the  south,  passes  through  the 
straits  of  Macassar  and  separates  the  two  small  islands 
of  Bali  and  Lombok.  We  will  now  follow  Wallace's 
description  ("  Malay  Archipelago  "),  with  various  omis- 
sions. 

"  It  is  now  generally  admitted  that  the  present  dis- 


MALAY  ARCHIPELAGO.  23 1 

tribution  of  living  things  on  the  surface  of  the  earth  is 
mainly  the  result  of  the  last  series  of  changes  that  it  has 
undergone.  Geology  teaches  us  that  the  surface  of  the 
land  and  the  distribution  of  land  and  water  is  every- 
where slowly  changing.  It  further  teaches  us  that  the 
forms  of  life  which  inhabit  that  surface  have,  during 
every  period  of  which  we  possess  any  record,  been  also 
slowly  changing.  As  to  the  Malay  Archipelago,  we  find 
that  all  the  wide  expanse  of  sea  which  divides  Java, 
Sumatra,  and  Borneo  from  each  other,  and  from  Malacca 
and  Siam,  is  so  shallow  that  ships  can  anchor  in  any 
part  of  it,  since  it  rarely  exceeds  forty  fathoms  in  depth : 
and  if  we  go  as  far  as  the  line  of  a  hundred  fathoms,  we 
shall  include  the  Philippine  Islands  and  Bali,  east  of 
Java.  If,  therefore,  these  islands  have  been  separated 
from  each  other  and  the  continent,  by  subsidence  of  the 
intervening  tracts  ot  land,  we  should  conclude  that  the 
separation  has  been  comparatively  recent,  since  the 
depth  to  which  the  land  has  subsided  is  so  small. — But 
it  is  when  we  examine  the  zoology  of  these  countries 
that  we  find  what  Ave  most  require — evidence  of  a  very 
striking  character  that  these  great  islands  must  have 
once  formed  a  part  of  the  continent,  and  could  only  have 
been  separated  at  a  very  recent  geological  epoch.  The 
elephant  and  tapir  of  Sumatra  and  Borneo,  the  rhino- 
ceros of  Sumatra  and  the  allied  species  of  Java,  the 
wild  cattle  of  Borneo  and  the  kind  long  supposed  to  be 
peculiar  to  Java,  are  now  all  known  to  inhabit  some 
part  or  other  of  Southern  Asia.  None  of  these  large 
animals  could  possibly  have  passed  over  the  arms  of  the 
sea  which  now  separate  these  countries,  and  their  presence 
plainly  indicates  that  a  land  communication  must  have 


233  THE   DOCTRINE  OF  DESCENT. 

existed  since  the  origin  of  the  species.  Among  the 
smaller  mammals,  a  considerable  portion  are  common 
to  each  island  and  the  continent ;  but  the  vast  physical 
changes  that  must  have  occurred  during  the  breaking  up 
and  subsidence  of  such  extensive  regions  have  led  to  the 
extinction  of  some  in  one  or  more  of  the  islands,  and 
in  some  cases  there  seems  also  to  have  been  time  for  a 
change  of  species  to  have  taken  place.  Birds  and  insects 
illustrate  the  same  view,  for  every  family,  and  almost 
every  genus  of  these  groups  found  in  any  of  the  islands, 
occurs  also  on  the  Asiatic  continent,  and  in  a  great  num- 
ber of  cases  the  species  are  exactly  identical.  Birds 
offer  us  one  of  the  best  means  of  determining  the  law 
of  distribution  ;  for  though  at  first  sight  it  would  appear 
that  the  watery  boundaries  which  keep  out  the  land  quad- 
rupeds could  be  easily  passed  over  by  birds,  yet  prac- 
tically it  is  not  so ;  for  if  we  leave  out  the  aquatic  tribes 
which  are  pre-eminently  wanderers,  it  is  found  that  the 
others  (and  especially  the  Passeres,  or  true  perching 
birds,  which  form  the  vast  majority)  are  generally  as 
strictly  limited  by  straits  and  arms  of  the  sea  as  are 
quadrupeds  themselves.  As  an  instance,  among  the 
islands  of  which  I  am  now  speaking,  it  is  a  remarkable 
fact  .that  Java  posesses  numerous  birds  which  never  pass 
over  to  Sumatra,  though  they  are  separated  by  a  strait 
only  fifteen  miles  wide,  and  with  islands  in  mid-channel. 
Java,  in  fact,  possesses  more  birds  and  insects  peculiar  to 
itself  than  either  Sumatra  or  Borneo,  and  this  would 
indicate  that  it  was  earliest  separated  from  the  con- 
tinent; next  in  organic  individuality  is  Borneo;  while 
Sumatra  is  so  nearly  identical  in  all  its  animal  forms 
with  tlie   peninsula   of   Malacca,   that   we   may  saicly 


MALAY  ARCHIPELAGO.  233 

conclude  it  to  have  been  the  most  recently  dismembered 
island. 

"  The  Philippine  Islands  agree  in  many  respects  with 
Asia  and  the  other  islands,  but  present  some  anomalies 
to  indicate  that  they  were  separated  at  an  earlier  period, 
and  have  since  been  subject  to  many  revolutions  in  their 
physical  geography. 

"Turning  our  attention  now  to  the  remaining  portion 
of  the  Archipelago,  we  shall  find  that  all  the  islands, 
from  Celebes  to  Lombock  eastward,  exhibit  almost  as 
close  a  resemblance  to  Australia  and  New  Guinea  as  the 
Western  Islands  do  to  Asia,  It  is  well  known  that  the 
natural  productions  of  Australia  differ  from  those  of  Asia 
more  than  those  of  any  of  the  four  ancient  quarters  of 
the  world  differ  from  each  other.  Australia,  in  fact, 
stands  alone  ;  it  possesses  no  apes  or  monkeys,  no  cats 
or  tigers,  wolves,  bears,  or  hyenas,  no  deer  or  antelopes, 
sheep  or  oxen,  no  elephant,  horse,  squirrel  or  rabbit ; 
none,  in  short,  of  those  familiar  types  of  quadruped 
which  are  met  with  in  every  other  part  of  the  world. 
Instead  of  these,  it  has  Marsupials  only,  kangaroos  and 
opossums,  wombats  and  the  duck-billed  platypus.  In 
birds  it  is  almost  as  peculiar.  It  has  no  woodpeckers 
and  no  pheasants,  families  which  exist  in  every 
other  part  of  the  world  ;  but  instead  of  them  it  has 
the  mound-making  brush-turkeys,  the  honeysuckers,  the 
cockatoos,  and  the  brush-tongued  lories,  which  are  found 
nowhere  else  upon  the  globe.  All  these  striking  pecu- 
liarities are  found  also  in  those  islands  which  form  the 
Austro-Malayan  division  of  the  Archipelago. 

"  The  great  contrast  between  the  two  divisions  of  the 
Archipelago  is  nowhere    so  abruptly  exhibited    as   on 


234  THE   DOCTRINE  OF   DESCENT. 

passing  from  the  island  of  Bali  to  that  of  Lomboclc, 
where  the  two  regions  are  in  closest  proximity.     In  Bali 
we  have  barbets,  fruit  thrushes,  and  woodpeckers  ;  on 
passing  over  to  Lombock  these  are  seen  no  more,  but 
we   have   abundance  of  cockatoos,   honeysuckers,   and 
brush-turkeys,  which  are  equally  unknown  in  Bali  or  in 
any  island  further  west.     The  strait  is  here  fifteen  miles 
wide,  so  that  we  may  pass  in  two  hours  from  one  great 
division  of  the  earth  to  another,  differing  as  essentially 
in  their  animal  life  as  Europe  does  from  America.^     It 
we  travel  from  Java  or  Borneo  to  Celebes  or  the   Mo- 
luccas, the  difference  is  still  more  striking.     In  the  first, 
the  forests  abound  in  monkeys  of  many  kinds,  wild  cats, 
deer,  civets  and  others,  and  numerous  varieties  of  squirrels 
are  constantly  met  with.  In  the  latter,  none  of  these  occur, 
but  the  prehensile-tailed  cuscus  is  almost  the  only  ter- 
restrial mammal  seen,  except  wild  pigs,  which  are  found 
in  all  the  islands,  and  deer  (which  have  probably  been 
recentlyintroduced)  inthe  Celebes  and  the  Moluccas.  The 
birds  which  are  most  abundant  in  the  Western  islands 
are  woodpeckers,   barbets,    trogons,  fruit-thrushes,   and 
leaf-thrushes ;  they  are  seen  daily,  and  form  the  great 
ornithological  features  of  the  country.     In  the  Eastern 
islands  these  are  absolutely  unknown,  honeysuckers  and 
small  lories  being  the  most  common  birds  ;   so  that  the 
naturalist  feels  himself  in  a  new  world,  and  can  hardly 
realize  that  he  has  passed  from  the  one  region  to  the  other 
in  a  few  days,  without  ever  being  out  of  sight  of  land. 

"  The  inference  that  we  must  draw  from  these  facts 
is  undoubtedly  that  the  whole  of  the  islands  eastwards, 

*  This  is  too  vaguely  expressed.     It  would  be  nearer  the  mark  to  say,  ai 
Europe  does  from  South  America.     (O.  Schmidt.) 


FORMER  PACIFIC   CONTINENT.  235 

beyond  Java  and  Borneo,  do  essentially  form  a  part  of  a 
former  Australian  or  Pacific  continent,  although  some  of 
them  may  never  have  been  actually  joined  to  it.  This 
continent  must  have  been  broken  up  not  only  before  the 
Western  islands  were  separated  from  Asia,  but  pro- 
bably before  the  extreme  south-eastern  portion  of 
Asia  was  raised  above  the  waters  of  the  ocean  ;  for  a 
great  part  of  the  land  of  Borneo  and  Java  is  known  to 
be  geologically  of  quite  recent  formation;  while  theveri- 
great  difference  of  species,  and  in  many  cases  of  genera 
also,  between  the  productions  of  the  Eastern  Malay 
islands  and  Australia,  as  well  as  the  great  depth  of  the 
sea  now  separating  them,  all  point  to  a  comparatively 
long  period  of  isolation." 

"  It  is  interesting  to  observe  among  the  islands  them- 
selves how  a  shallow  sea  always  intimates  a  recent  land 
connection.  The  Aru  islands,  Maisol  and  Waigiou,  as 
well  as  Jobic,  agree  with  New  Guinea  in  their  species  of 
mammalia  and  birds  much  more  closely  than  they  do 
with  the  Moluccas,  and  we  find  that  they  are  all  united  to 
New  Guinea  by  a  shallow  sea.  In  fact,  the  icx)-fathom 
line  round  New  Guinea  marks  out  accurately  the  range 
of  the  true  Paradise  birds. 

"  It  is  further  to  be  noted — and  this  is  a  very  interesting 
point  in  connection  with  theories  of  the  dependence  of 
special  forms  of  life  on  external  conditions — that  this 
division  of  the  Archipelago  into  two  regions  character- 
ized by  a  striking  diversity  in  their  natural  productions, 
does  not  in  any  way  correspond  to  the  main  physical  or 
climatal  divisions  of  the  surface."  We  will  further 
quote  only  the  following :  '*  Borneo  and  New  Guinea,  as 
alike  physically  as    two  distinct  countries  can  be,  are 


236  THE  DOCTRINE  OF  DESCENT. 

zoologically  wide  as  the  poles  asunder  ;  while  Australia, 
with  its  dry  winds,  its  open  plains,  its  stony  deserts,  and 
its  temperate  climate,  yet  produces  birds  and  quadru- 
peds which  are  closely  related  to  those  inhabiting  the 
hot,  damp,  luxuriant  forests  which  everywhere  clothe  the 
plains  and  mountains  of  New  Guinea." 

Wallace  gives  the  most  specific  proofs  that,  as  the 
parts  of  this  Archipelago  approach  one  another  like 
separated  extremities  of  two  continents,  they  bring  with 
them  two  entirely  different  fauna.  Similarly,  the  Medi- 
terranean and  West  Indian  Archipelagos  are  devoid  of 
any  peculiar  character,  and  are  completely  dependent 
on  the  adjacent  continents  for  their  animal  life  and 
vegetation.  We  have  already  discussed  Madeira  and  its 
land  snails.  Insular  faunas  therefore  do  not  require  the 
hypothesis  of  more  centres  of  creation  than  are  offered 
by  the  continents ;  and  Riitimeyer  has  endeavoured 
to  trace  the  extraction  of  birds  and  mammals  to  two 
centres  of  derivation.  A  great  series  of  animal-geo- 
graphical facts  is  explicable  only  on  the  hypothesis  of  the 
former  existence  of  a  southern  continent,  of  which  the 
Australian  mainland  is  a  remnant.  The  present  Marsu- 
pials are  concentrated  in  Australia.  Their  occurrence 
m  the  south-western  portion  of  the  Malay  Archipelago, 
including  New  Guinea,  seems  like  a  radiation  from  that 
centre.  No  single  token  makes  it  appear  that  the 
Marsupials  existing  in  former  periods  in  the  northern 
hemisphere,  from  the  Jura  forwards,  had  migrated  to 
meet  those  which  were  pressing  on  from  the  southern 
continent  towards  the  equator.  Only  as  to  the  opossum, 
so  widely  extended  in  South  America,  could  a  question 
arise,  which  is  however  solved  by  the  examination  of  a 


SOUTHERN  FAUNA.  237 

host  of  congeners,  one  and  all  alien  to  the  population 
predominant  in  America,  and  indicating  importation 
probably  in  the  Tertiary  period  ;  unless  it  be  assumed, 
with  Riitimeyer,  *'  that  implacental  mammals  were 
created  out  of  Australia  as  well  as  in  it." 

Among  the  first  to  be  mentioned  are  the  wingless 
birds,  that  is,  those  which  are  anatomically  and  syste- 
matically connected,  and  which  we  now  find  scattered 
over  continents  and  some  of  the  larger  islands.  The 
cassowary  of  New  Holland  and  America,  the  extinct 
giant  birds  of  Madagascar  and  New  Zealand,  the 
African  ostrich,  which  has  advanced  from  the  south 
northwards,  cannot  have  originated  in  their  present 
isolation.  The  same  considerations  are  forced  upon 
us  by  the  mammals  named  Bruta  by  Linnaeus,  and 
by  modern  zoologists  termed  Edentata,  by  reason  of 
their  imperfect  dentition,  among  which,  accepting  the 
latter  definition,  must  be  included  the  Ornithorhyncus, 
or  duck-mole  of  Tasmania.  These  duck-moles  incon- 
testibly  occupy  the  lowest  grade  among  the  mamm?ls 
now  extant ;  but  the  other  true  Edentata  are  no  less 
alien  to  the  higher  orders,  and  their  occurrence  in  South 
America  on  the  one  hand,  and  in  South  Africa  and 
South  Asia  on  the  other,  as  well  as  \he  impossibility 
of  tracing  them  from  a  common  centre  in  the  northern 
hemisphere,  points  to  the  vanished  land  of  the  south, 
where  perhaps  the  home  of  the  progenitors  of  the  Maki 
of  Madagascar  may  also  be  looked  for. 

"  Or,"  says  Riitimeyer,  "  does  the  hypothesis  of  a  Polar 
land,  once  possessing  an  abundance  of  animal  life,  partly 
covered  by  the  ocean  and  partly  by  a  coat  of  ice,  appear 
an  unfounded  assumption  to  us  who  now  witness  the 


238  THE   DOCTRINE  OF  DESCENT. 

elevation  of  a  similar  frozen  surface  in  the  northern 
hemisphere,  and  are  surrounded  in  the  Alps  by  a  still 
existing — in  our  glacial  drift  by  a  scarcely  vanished — 
arctic  scene?  Or  need  the  conjecture  that  the  almost 
exclusively  graminivorous  and  insectivorous  Marsupials, 
sloths,  armadilloes,  ant-eaters,  and  ostriches,  once  pos- 
sessed an  actual  point  of  union  in  a  southern  continent, 
of  which  the  present  flora  of  Terra  del  Fuego,  the 
Cape,  and  Australia,  must  be  the  remains, — need  this 
conjecture  raise  difficulties  at  a  moment  when  from  their 
fossil  remains  Heer  restores  to  our  sight  the  ancient 
forests  of  Smith's  Sound  and  Spitzbergen  ?" 

Having  ventured  to  reconstruct  the  southern  conti- 
nent, with  its  strange  fauna,  of  which  the  remains  are 
so  widely  dispersed,  Riitimeyer  casts  about  for  more 
specific  evidence  in  favour  of  the  hypothesis  to  which 
the  course  of  the  world's  formation  everywhere  gives 
rise,  that  fresh-water  animals  and  likewise  terrestrial 
animals  came  up  from  the  sea.  Hence  the  notably 
small  division  of  sirenoid  fish  (Lepidosiren,  Proto- 
pterus),  which  breathe  air  during  the  dry  season  of  the 
year,  must  not  be  considered  reptiles  adapting  them- 
selves to  aquatic  life,  but  the  reverse.  The  organ  which 
in  fish  served  as  a  hydrostatic  apparatus,  the  swim  blad- 
ders, becomes  in  them  the  lung.  Thus  we  must  go 
back  from  terrestrial  to  aquatic  tortoises,  and  from  them 
to  those  denizens  of  the  sea  which  are  allied  to  the 
Enaliosaurians,  so  frequent  in  the  Jurassic  strata.  The 
evolutionary  and  biographical  history  of  the  land  crabs 
shows  us  in  the  plainest  manner  how  the  inhabitant  of 
the  sea  becomes  a  terrestrial  animal  ;  a  special  problem 
which,  as  we  have  already  mentioned,  Fritz  Miiller  has 


MODIFICATIONS   OF   FISHES.  239 

completely  solved  and  capitalized,  in  his  essay,  "for 
Darwin."  Of  the  sirens,  commonly  but  erroneously 
reckoned  among  the  Cetacea,  and  of  which  the  majority 
prefer  remaining  at  the  mouths  of  large  estuaries,  one 
entire  species  has  penetrated  into  the  great  inland  lakes 
of  Africa ;  and  certain  species  of  salmon  as  well  as  the 
sturgeons,  which  alternate  periodically  between  salt  and 
fresh  water,  are  in  the  phase  of  gradually  forsaking 
ocean  life.  From  my  special  experience,  I  may  add 
that  the  brackish  water  sponges  are  certainly  dependent 
on  the  marine  families,  and  that  the  fresh-water  species 
unmistakably  point  to  these  brackish  forms. 

If  in  all  these  cases  we  are  dealing  with  gradual 
transformation,  and  more  or  less  voluntary  adaptation, 
there  is  no  lack  of  conspicuous  instances  of  forcible 
and  almost  sudden  severance  ;  of  upheavals  by  which 
former  sections  of  the  ocean  became  inland  seas.  What 
were  the  modifications  undergone  by  the  fish  and  crabs 
secluded  v/ith  them,  is  shown  by  the  fine  observations 
of  Loven  on  the  animals  of  Lakes  Wener  and  Wetter, 
and  of  Malmgren  on  those  of  Ladoga.  The  latter  brings 
evidence  that  the  salmon-trout  of  the  Alps  (Salmo 
salvclinus)  is  derived  from  the  Polar  Sea,  and  is  own 
brother  to  the  Scandinavian  Salmo  alpinus. 

Riitimeyer  pronounces  the  opinion  that  by  more 
minutely  tracing  the  relations  of  the  fresh-water  fauna 
to  those  of  the  denizens  of  the  ocean,  the  cosmopoli- 
tanism of  fresh-water  animals  will  be  explained,  as  well 
as  the  relation  of  antarctic  to  arctic  life.  For  the  pre- 
sent, however,  these  two  great  animal  groups,  as  regards 
the  higher,  warm-blooded  classes,  are  somewhat  sharply 
contrasted.     It  is  only  from  scanty  remains   that  we 


2:4.0  THE  DOCTRINE  OF  DESCENT. 

know  that  so  early  as  the  Jurassic  era,  the  northern 
hemisphere  was  peopled  by  Marsupials,  but,  it  is  evident, 
not  densely.  We  must  suppose  that,  retaining  their 
character,  the  Marsupials  of  the  southern  continent 
tested  and  proved  their  powers  of  adaptation,  whereas 
on  the  other  side  of  the  equator  a  race  of  mammals  cf 
completely  different  cast  proceeded  from  them.  This  is 
the  race  which  still  characterizes  the  whole  surface  of 
the  earth  from  the  north  to  the  point  of  contact  with 
the  more  stable  remnants  of  antarctic  life.  While  with 
reference  to  their  origin  we  can  appeal  only  to  reason 
and  inference,  the  historical  connection  between  the 
mammalia  now  peopling  the  Old  and  the  greater  part 
of  the  New  World,  and  their  predecessors  up  to  the 
most  ancient  Tertiary  periods,  is  manifest  to  our  eyes. 

The  remains  of  the  earliest  mammals  here  to  be  con- 
sidered, are  found  in  the  Eocene  deposits  of  Switzerland, 
and  in  corresponding  strata  in  France  and  the  south  oi 
England.  From  the  southern  edge  of  the  Jurassic 
plateau,  neither  the  Alps  nor  any  other  land  was  visible, 
and  the  ocean  which  washed  its  shores  has  been  traced 
as  far  as  China.  The  mammalia  of  this  period,  as  far  as 
they  are  known,  amount,  according  to  the  synopsis  made 
by  Rutimeyer  in  1867,  to  at  least  70  species.  The 
majority  are  ungulate,  therefore  Graminivora  ;  of  these, 
by  far  the  greater  number  Pachydermata.  Now,  when 
the  entire  world  scarcely  maintains  so  many  Pachyderms, 
the  proportions  are  quite  altered.  In  Europe,  the  pig 
alone  represents  this  division,  and  Ruminants  everywhere 
predominate.  In  its  present  animal  population,  Africa 
might  be  approximately  compared  to  Eocene  Europe. 
But  as  to  these  Ungulates  must  be  added  a  large  num- 


TERTIARY  FAUNA.  24I 

ber  of  Carnlvora,  resembling  the  Viverrida  (polecats, 
martens,  &c.)  and  hyenas,  and  as  viverridae  exist  in 
Africa  as  well  as  in  Asia,  and  as,  moreover,  the  musk 
ruminants  represented  in  this  primitive  fauna  are 
now  likewise  Asiatic  and  African,  and,  finally,  as  the 
French  opossums  of  those  ages  still  live  in  Central  and 
South  America,  **  we  gain  an  impression  that  the  most 
ancient  Tertiary  fauna  of  Europe  is  the  source  of  a 
truly  continental  animal  society  now  represented  in  the 
tropical  zone  of  both  worlds,  but  most  emphatically  in 
Africa." 

Far  more  heterogeneous  is  the  picture  of  the  higher 
animal  life  of  the  middle  and  more  recent  Tertiary 
periods  which  we  reconstruct  from  the  numerous  and  in 
parts  highly  prolific  repositories  of  these  remains.  To 
draw  narrower  limits  within  these  periods  is  imprac- 
ticable ;  from  place  to  place,  from  stratum  to  stratum, 
there  is  coherence  ;  nowhere  does  a  species  appear  that 
might  not  be  derived  from  another ;  and  our  authority 
says  that  anatomy,  morphology,  palaeontology,  and  geo- 
graphical distribution,  seemed  to  impress  no  doctrine 
upon  him  with  such  energy  and  pertinacity  as  that 
separate  species  of  a  genus,  species  without  any  historical 
and  therefore  without  any  previous  local  link  to  any 
original  stock,  do  not  exist."  The  most  celebrated 
repository  of  Tertiary  mammals  is  Pikermi,  a  short 
distance  from  Athens,  an  accumulation  of  skeletons 
complete  and  in  fragments,  which  pre-supposes  a  pro- 
fusion of  animals,  of  which  at  any  rate  the  most  densely 
inhabited  regions  of  Africa  may,  according  to  Living- 
stone's descriptions,  give  us  an  idea. 

Again  the  Carnivora  give  way  to  the  Graminivora, 


242  THE  DOCTRINE  OF  DESCENT. 

though  the  feline  beasts  of  prey  make  themselves  con- 
spicuous ;  and  among  the  great  Tertiary  beasts  of  prey 
are  some  which  have  a  range  as  great  as  the  tiger  of  the 
present  age.  The  territory  of  the  extinct  sabre-toothed 
tiger  (Machairodus)  at  that  time  extended  over  a  great 
part  of  America  and  Europe.  Let  us  also  mention  that 
the  canine  animals  appear  somewhat  later,  and  that  the 
bears  are  of  still  more  recent  origin.  At  this  period  the 
most  abundant  material  still  favours  the  ungulates. 
Cloven  feet  still  preponderate.  Pigs  and  musk-animals 
are  the  most  constant.  But  the  tapir,  in  shape  like  the 
older  forms,  is  now  joined  by  the  rhinoceros,  the  true 
horses,  and  the  elephants.  If  the  origin  of  the  rhinoceros 
is  somewhat  obscure,  the  extraction  of  the  mastodon,  the 
older  form  of  the  elephant,  is  hitherto  quite  unknown.'^ 
And  yet  though  we  search  in  vain  through  the  known 
mammalian  fauna  of  the  Eocene  period  for  the  most 
nearly  allied  parent  forms,  there  are  numerous  tokens 
that  even  in  Europe  and  Asia,  "  most  of  the  Eocene 
must  be  regarded  as  the  true  root  forms  of  the  Miocene 
genera."  (R.)  This  is  shown  by  the  discoveries  at 
Nebraska  in  North  America,  where  important  genera, 
which,  like  the  Palaeotherium,  disappeared  from  the  Old 
World  in  the  Eocene  period,  took  refuge  in  company 
with  newer  genera.  We  likewise  find  there,  intermediate 
forms  between  the  lama  and  the  camel,  which  in  this 
case  alone  gives  its  true  significance  to  the  once  un- 
meaning word,  vicarious  genera.  At  Nebraska  we 
moreover  find  the  triple-hoofed  horse  (Anchitherium), 
and  we  hence  know  the  origin  of  the  single-hoofed 
horse  of  the  Old  and  New  Worlds. 

What  has  happened  in  the  Old  World  since  that  age 


DISTRIBUTION   OF  ANIMALS  IN  AMERICA.       243 

is  confined  to  the  extinction  of  many  Pachydermata,  a 
displacement  of  the  rhinoceros,  elephant,  tapir,  and 
hippopotamus,  and  an  extremely  abundant  development 
of  the  true  ruminants  and  the  cattle  which  proceeded 
from  them  with  an  exaggerated  form  of  head.  Bears 
and  canine  species  occupy  the  territory  where  viverridae 
and  hyenas  once  predominated ;  but  as  "numerous  locally 
and  historically  limited  species,  a  large  number — among 
the  smaller  fauna  a  majority — of  Miocene  races  remain  in 
possession  of  the  ancient  and  probably  constantly  increas- 
ing habitat."  (R.)  "  In  this  gradual  change  of  things, 
no  one  will  be  able  to  discern  aught  but  phenomena  of 
the  same  order  of  which  we  are  still  the  witnesses."  (R.) 
How  circumstances  occurred  in  America  has  been 
described  in  a  masterly  style  by  Rutimeyer  as  follows  : 
**  America  affords  a  basis  for  the  distribution  of  animals 
completely  different  from  that  of  the  Old  World. 
In  the  latter,  ridges,  open  only  in  places,  divide  the 
entire  continent  into  mountainous  zones,  and  corres- 
pond to  the  distribution  of  temperature.  Thus  in  a 
twofold  manner  they  prescribe  a  definite  range  east 
and  west  to  the  extension  of  animals ;  while  a  migra- 
tion from  north  to  south  is  impeded  less  by  the  height 
of  the  mountains  than  that  on  their  summit  the  north 
comes  into  contact  with  the  scorching  south.  Behind 
this  wall,  moreover,  in  the  expanse  from  the  Caspian 
Sea  to  China,  there  is  a  zone  of  steppes  and  deserts 
which  fences  in  the  animals  more  effectually  than  the 
mountain  chains.  In  America,  not  beasts  of  prey  alone, 
but  graminivora  also,  may  advance  without  hindrance 
from  the  regions  of  the  lichen  on  the  Mackenzie  River, 
through  the  pine  forests  of  Lake  Superior,  to  the  land  of 
17 


244  1'"^  DOCTRINE  OF  DESCENT. 

the  magnolia  in  Mexico  ;  40** — 50^  of  latitude  separate 
the  extremes  which  meet  in  the  Himalayas,  and  the  vast 
plains  and  huge  river  systems  seem  almost  to  solicit 
immigration.  The  accordance  of  the  whole  faunas  of 
Mexico  and  Guiana,  moreover,  shows  how  little  the 
isthmus  of  Panama  checks  the  advance  to  South 
America,  where  again  one  mighty  fluvial  system  trenches 
upon  the  other  without  any  lofty  partitions  ;  nor  is  there 
any  arid  desert  in  the  whole  extent  from  the  Canadian 
seas  to  Patagonia. 

"We  shall  probably  not  be  wrong  in  ascribing  the 
remarkable  extension  of  fossil  and  present  mammals  of 
America  in  a  great  measure  to  this  circumstance.  As 
we  have  seen,  the  Miocene  fauna  of  Nebraska  is  the 
offspring  of  the  Eocene  fauna  of  the  Old  World.  The 
Pliocene  animals  of  Niobrara,  which  are  burled  in  the 
same  district  as  Nebraska,  but  on  more  recent  arenaceous 
strata,  still  further  corroborate  this  statement :  elephants, 
tapirs,  and  many  species  df  horses,  scarcely  differ  from 
those  of  the  Old  World  ;  the  pigs,  judging  by  their 
dentition,  are  descendants  of  European  miocene 
Pala^ochoeridee.  The  ruminants  are  represented  by  the 
same  genera,  and  partially  by  the  same  species,  as  in 
the  analogous  strata  of  Europe,  as  deer,  sheep  and 
buffaloes  ;  neither  do  the  carnivora  or  the  minute  animal 
life  offer  an  exception.  Many  genera  of  an  entirely 
Old-World  cast  have  in  the  lapse  of  time  penetrated 
far  into  South  America,  and  there  died  out  shortly 
before  the  arrival  of  man,  or  perhaps  by  his  co-opera- 
tion, as  was  the  case  with  the  two  species  of  mammoth 
of  the  Cordilleras  and  the  South  American  horse,  whose 
present  successors  reached  this  insular  continent  by  a 


DISTRIBUTION   OF  ANIMALS  IN   AMERICA.      245 

far  shorter  road.  Even  a  species  of  antelope  and  two 
other  horned  ruminants  (Leptotherium)  found  their  way 
to  Brazil.  Two  sorts  of  tapir,  of  which  the  dentition, 
even  in  Cuvier's  eyes,  is  scarcely  distinguishable  from 
(he  Indian  species;  two  species  of  pigs,  still  bearing 
in  their  milk-teeth  unmistakable  characters  of  their 
aboriginal  form  ;  and  a  number  of  deer,  besides  the 
lamas,  a  later  and  originally  American  offshoot  of  the 
Eocene  Anoplotheria — are  one  and  all  living  remnants 
of  this  ancient  colony  from  the  East,  which  did  not 
reach  its  dwelling-place  without  copious  losses  on 
its  long  pilgrimage.  It  can  scarcely  be  doubted  that 
many  of  the  beasts  of  prey  which  in  the  Diluvium  of 
South  America  retained  their  family  character  more 
than  they  do  now,  must  have  arrived  there  in  the  same 
manner.  Let  us  now  remember  that  even  the  Eocene 
Caenopithecus  of  Egerkingen  distinctly  pointed  to  the 
present  apes  of  America,  and  that  the  Didelphidse  (Opos- 
sums) lie  buried  in  the  same  European  soils.  It  might 
almost  appear  that  it  was  pre-eminently  the  division 
of  arboreal  quadrumana  which,  with  the  opossums, 
domesticated  itself  in  the  vast  forests  of  their  new  abode, 
and,  receiving  a  fresh  impulse,  gave  rise  to  a  multitude 
of  special  forms,  without  however  having,  even  in  the 
present  times,  reached  the  pitch  of  development 
attained  by  their  cousins  who  had  remained  behind  in 
the  Old  World. 

"  We  may  now  appropriately  return  to  our  previous 
remark  that  this  migration  of  animals  did  not  find  the 
south  of  the  New  World  destitute  of  mammals,  but 
rather  already  occupied  by  the  toothless  representatives 
of  antarctic,  or  at  least  of  southern  animal  life.     The 


246  THE   DOCTRINE   OF   DESCENT. 

diluvial  fauna  of  South  America  collected  by  Lund, 
Castlenau,  and  Weddell,  from  the  Brazilian  caves,  and 
the  alluvium  of  the  Pampas,  among  the  118  species  cited, 
actually  includes,  in  addition  to  those  already  mentioned, 
as  being  of  probably  Old-World  pedigree,  no  less  than 
35  species  of  Edentata,  and  these  animals  of  consider- 
able bulk.  Not  reckoning  the  36  rodents  and  bats,  and 
the  smaller  fauna  in  general,  they  constitute  nearly  half 
of  tlie  larger  diluvial  animals  of  South  America.  The 
assemblage  of  Edentata  previously  settled  in  these 
regions  thus  held  their  own  against  the  invasion  from 
the  north. 

It  is  comprehensible  that  the  same  external  causes 
which  led  the  march  of  the  children  of  the  north  con- 
stantly further,  may  likewise  have  invited  the  members 
of  the  antarctic  fauna  to  extend  themselves  northwards. 
As  we  even  now  encounter  the  incongruous  forms  of 
the  sloth,  the  armadillo,  and  the  ant-eater  in  Guatemala 
and  Mexico,  in  the  midst  of  a  fauna  in  great  part  con- 
sisting of  races  still  represented  in  Europe,  we  also  find, 
even  in  diluvial  eras,  gigantic  sloths  and  armadillos 
ranging  far  into  the  north.  Megalonyx  Jeffersoni,  and 
Mylodon  Harlemi,  sentries  of  South  American  origin 
thrown  out  as  far  as  Kentucky  and  Missouri,  are  a 
phenomenon  as  heterogeneous  in  the  land  of  the  bison 
and  the  deer,  as  is  the  mastodon  in  the  Andes  of  Nev/ 
Granada  and  Bolivia.  Over  the  whole  enormous  extent 
of  both  portions  of  the  New  Continent,  the  mixture 
and  interpenetration  of  two  mammalian  groups  of  com- 
pletely diverse  families,  constitutes  the  most  conspicuous 
feature  of  its  fauna ;  and  it  is  significant  that  each 
group  increases  in  the  abundance  of  its  representatives 


CAUSES  OF  GEOGRAFHICAL  DISTRIBUTION.      247 

and  in  the  originality  of  their  appearance  as  we  approach 
its  point  of  derivation." 

Hence,  on  both  sides  of  the  ocean,  north  of  the  very 
sinuous  boundary  of  the  antarctic  or  southern  fauna, 
we  find  ourselves  still  in  the  midst  of  the  diluvial  animal 
world,  which  extended  itself,  by  a  bridge  in  the  vicinity 
of  the  North  Pole,  from  the  old  continents  to  the 
mainland  of  America,  and  there  for  a  longer  period 
retained  its  ancient  appearance  in  the  mastodons  and 
horses. 

There,  as  well  as  here,  the  present  order  of  things — 
the  cantonment  of  animals — has  been  in  many  ways 
determined  and  modified  by  mighty  glacifications  and 
prolonged  periods  of  refrigeration.  Hence  the  accord- 
ance of  so  many  plants  of  the  extreme  north  with 
Alpine  plants  after  the  Eocene  vegetation  had  made  its 
entry  from  the  east.  Since  that  age,  the  reindeer  has 
been  forced  back  to  the  north,  and  the  musk  ox  has 
been  expelled  and  exterminated  from  the  Old  World. 
The  elephants,  fleeing  before  the  ice,  have  not  returned  ; 
and  the  mammoth,  immigrating  with  a  rhinoceros  from 
the  north-east,  has  been  destroyed  with  his  associate. 
Others  of  his  comrades,  such  as  the  primaeval  ox,  died 
out  only  a  few  centuries  ago  as  wild  cattle  ;  others, 
like  the  buffalo  and  the  beaver,  are  nearly  extinct  as 
denizens  of  Europe ;  and  others  again,  the  deer  and 
roe- deer,  will  perish  with  the  forests  and  the  game-laws. 
But:  of  almost  all  the  species  of  which  we  search  lor 
the  extraction.  Palaeontology  supplies  us  with  the  his- 
tory and  derivation ;  and  in  derivation  we  find  the 
causes  of  geographical  distribution  sketched  in  vivid 
outlines. 


248  THE  DOCTRINE  OF  DESCENT. 


XL       - 

The  Pedit,ree  of  Vertebrate  Animals. 

The  final  result  towards  which  the  doctrine  of  Descent 
directs  its  efforts,  is  the  pedigree  of  organisms.  To 
work  it  out  is  to  collect  the  almost  inconceivable  pro- 
fusion of  facts  accumulated  in  the  course  of  about  a 
century  by  descriptive  botany  and  zoology,  including 
comparative  anatomy  and  the  history  of  development, 
and  to  submit  the  existing  special  hypotheses  to  a  minute 
scrutiny  and  renewed  verification.  We  have  therefore 
claimed  in  behalf  of  the  doctrine  of  Derivation  the 
privilege  on  which  the  progress  of  science  generally 
relies — that  of  investigating  according  to  determined 
points  of  view,  and  accepting  probabilities  as  truth  in 
the  garb  of  scientific  conjecture  or  hypothesis.  It  is 
manifest  that  when  the  doctrine  of  Descent  first  made 
its  appearance  with  the  arguments  proposed  by  Darwin, 
it  was  only  possible  to  indicate  the  most  general  outlines 
of  this  great  pedigree,  which  it  was  the  special  task  of 
the  new  direction  of  science  to  demonstrate  in  all  its 
details.  But  however  and  wherever  specific  research 
was  attempted,  either  the  results  contributed  the  form 
of  some  part  of  the  great  pedigree,  or  there  was,  from 
the  first,  reason  to  pre-suppose  certain  kinships,  and  the 


PEDIGREE  OF  VERTEBRATE  ANIMALS.  249 

conjecture  was  tested.  The  further  an  inquirer  has 
carried  his  survey  of  the  conditions  of  organization  in 
any  of  the  larger  groups,  the  less  will  he  be  able  to 
divest  himself  of  the  genealogical  idea  in  his  every  act 
and  thought. 

All  this  is  so  self-evident,  that  one  would  scarcely  sup- 
pose that  the  use  of  this  method  could  have  been  made 
a  subject  of  reproach  to  the  doctrine  of  Descent.  Never- 
theless, it  frequently  occurs,  and  the  champions  of  the 
doctrine  of  Descent  are  blamed  for  often  speaking  of 
mere  probabilities,  forgetting  that  even  in  cases  in  which 
the  probability  ultimately  proves  false,  the  refuted  hy- 
pothesis has  led  to  progress.  Of  this  the  science  of 
language  has  recently  borne  testimony.  It  is  well  known 
that  linguistic  comparison  within  the  family  of  Indo- 
'Germanic  tongues  suggested  the  reconstruction  of  the 
primitive  language  which  formed  their  common  basis. 
Johannes  Schmidt^*  now  proves  that  the  fundamental 
forms  disclosed  may  have  originated  at  widely  different 
periods,  and  hence  that  the  primitive  language,  regarded 
as  a  whole,  is  a  scientific  fiction.  Nevertheless,  inquiry 
was  essentially  facilitated  by  this  fiction,  and  with  it 
was  intimately  connected  the  formation  of  a  pedigree  of 
the  Indo-Germanic  linguistic  family,  as  a  hypothesis 
supported  by  many  indications.  A  bifurcation  was 
assumed  into  a  South  European  language,  with  Greek, 
Italian,  and  Celtic  ramifications,  and  another  language, 
from  a  second  division  of  which  proceeded  the  funda- 
mental language  of  North  Europe  and  the  Aryan  fun- 
damental language.  Although  Johannes  Schmidt  has 
demonstrated  that  this  pedigree  is  false,  as  the  existence 
of    Slavo  -  Lettish    shows    the    impossibility   of    the    first 


250  THE   DOCTRINE   OF   DESCENT. 

division   assumed,  the   value  of  the   hypothesis   is   undi- 
minished.    It  was  the  road  to  truth. 

In  our  science  Haeckel  has  made  the  most  extensive 
use  of  the  right  of  devising  hypothetical  pedigrees  as 
landmarks  for  research.  It  matters  nothing  that  he  has 
repeatedly  been  obliged  to  correct  himself,  or  that  others 
have  frequently  corrected  him  ;  the  influence  of  these 
pedigrees  on  the  progress  of  the  zoology  of  Descent  is 
manifest  to  all  who  survey  the  field  of  science,  not  to 
mention  that  in  the  last  ten  years  a  series  of  researches 
have  conclusively  fixed  their  results  in  good  pedigrees. 
As  we  propose  to  give  merely  an  introduction  to  the 
doctrine  of  Descent,  we  shall  content  ourselves  with 
showing  how  the  system  or  the  pedigree  is  constituted 
in  its  application  to  the  single  group  of  the  Vertebrata. 

Mammals. 


?  Enaliosaurians 


Primordial  Vertebrata. 
Annulosa. 

As  we  have  seen  above,  the  most  important  indications 
of  the  pedigree  of  the  species  are  contained  in  the  evo- 


PEDIGREE   OF   VERTEBRATE   ANIMALS.  25 1 

lutionary  history  of  the  individual.  But  though  all  verte- 
brate animals  testified  their  family  connection  by  agree- 
ing i7iter  se  in  the  distribution  of  the  germ  as  well  as  in 
the  fundamental  important  organs,  the  spinal  cord  and 
the  vertebral  column,  every  token  of  their  descent 
from  inferior  animals,  which  is  unconditionally  demanded 
by  the  theory,  seemed  to  be  entirely  wanting.  In  other 
words,  it  seemed  that  in  all  vertebrate  animals  the 
memory  of  their  original  derivation  had  been  obliterated 
by  curtailed  development  (comp.  p.  211).  Thus  the  case 
remained  until  Kowalewsky  a  few  years  ago  studied  the 
development  of  the  lancelet  (Amphioxus),  the  lowest 
vertebrate  animal  known,  and  showed  that  in  this  crea- 
ture the  typical  phenomena  of  vertebrate  development 


.:§t^t^!^^ 


ncelet  after  Kowalewsky. 


are  preceded  by  the  phases  required  by  the  theory. 
We  have  already  made  acquaintance  with  this  form  of 
development  (p.  51,  &c.),  and  we  here  again  point  out  its 
profound  significance.  It  is  only  when  the  Amphioxus 
has  passed  through  the  phase  of  the  vibrating,  sac-like 


252  THE  DOCTRINE   OF  DESCENT. 

gastrula  larva  that  the  future  dorsal  side  becomes  flat- 
tened, and  the  protuberances  arise,  which  shortly  after 
close  into  the  sheath  of  the  spinal  marrow,  while  beneath 
it  originates  this  important  cellular  column,  the  chorda 
dorsalis,  or  notochord.  With  this  the  lancelet  becomes 
a  vertebrate  animal,  and  the  preceding  phases  do  not 
(according  to  the  view  at  one  time  inculcated  by 
C.  E.  v.  Baer  respecting  such  phenomena)  recall  the 
inferior  and  undeveloped  in  general  by  the  absence 
of  differentiation,  but  they  agree  in  genesis  and  dis- 
tribution, in  the  differentiation  of  their  cellular  layers, 
and  in  their  totality,  with  the  Gastrula  phases  of  inver- 
tebrate animals. 

We  are  therefore  fully  justified  in  regarding  these 
first  incidents  in  the  evolution  of  the  Amphioxus  as  a 
reminiscence  of  the  roots  of  the  pedigree  of  the  Verte- 
brata  ;  and  this  direct  indication  of  the  descent  of 
vertebrate  from  invertebrate  animals  is  supported  by  a 
second  and  no  less  important  discovery  by  the  Russian 
naturalist.  It  is,  that  during  their  development  a  num- 
ber of  the  Tunicata  of  the  division  of  the  Ascidians 
temporarily  possess  a  spinal  cord,  and  the  rudiments 
of  a  vertebral  column.  Kowalewsky's  researches  have 
been  ratified  on  all  essential  points  and  in  many  ways 
extended  by  Kupfer,  and  the  facts  which  interest  us 
may  be  explained  by  the  diagram.  Fig.  23,  representing 
the  forepart  of  the  larva  of  an  Ascidian  in  a  somewhat 
advanced  stage.  The  bulk  of  the  Ascidian  larva  consists 
of  a  body  of  which  our  figure  shows  the  whole,  and  a 
rudder-like  tail.  The  appendages  projecting  from  the 
body  on  the  right  are  organs  of  adhesion,  by  means  of 
which  the  larva  fixes  itself  for  its  definitive  transforma- 


PEDIGREE   OF  VERTEBRATE  ANIMALSc 


253 


tion.      At   o  the   orifice   of  the   mouth    is   formed  ;    d 
developes  into  the  branchial  cavities  and  the  intestinal 


Fig.  23. 


canal,  and  we  will  incidentally  remark  that  in  the  lance- 


254  THE   DOCTRINE  OF   DESCENT. 

let  also,  the  anterior  end  of  the  primitive  intestine 
becomes  the  branchial  cavity.  But  with  reference  to  the 
vertebrate  animals,  the  most  important  parts  of  the  Asci- 
dian  larva  are  the  following.  It  possesses  a  true  spinal 
cord  with  a  vesicularly  expanded  brain  (ra).  The  distri- 
bution and  position  of  this  organ  agrees  accurately  with 
the  corresponding  parts  of  the  vertebrate  animal,  and 
Kupfer  has  even  discerned  the  rudiments  of  nerves 
{s  s  s),  which,  if  the  observation  is  confirmed,  will  still 
more  incontrovertibly  establish  the  homology  of  the 
organ  in  question  with  the  spinal  cord  of  the  Vertebrata 
and  the  nerves  proceeding  from  it  in  pairs.  But  we 
know  that  it  is  not  the  spinal  cord  alone,  but  its  combi- 
nation with  the  vertebral  column  which  constitutes  the 
characteristic  feature  of  the  vertebrate  animal.  This  ver- 
tebral column  the  Ascidian  larva  likewise  possesses  (6^) 
in  the  form  of  the  noto-chord,  and,  as  in  the  vertebrate 
animal,  this  embryonic  vertebral  column  Hes  between 
the  intestine  and  the  spinal  cord.  So  far  goes  the  ac- 
cordance ;  henceforth,  the  development  of  this  part,  so 
important  to  the  vertebrate  animal,  becomes  retrogres- 
sive in  the  Ascidian.  The  rudder-like  tail,  with  the 
spinal  cord  contained  in  it,  and  the  noto-chord,  are  cast 
off  when  the  animal  becomes  fixed  ;  the  larval  brain 
which  promised  so  well,  shrinks  into  an  insignificant 
nervous  ganglion,  and  the  complete  animal  gives  no 
cause  for  suspecting  its  analogy  with  the  Vertebrata. 

These  laborious  observations  prove  that  the  Vertebrata 
are  not  the  sole  proprietors  of  the  spinal  cord  and  verte- 
bral column,  but  received  these  organs  as  a  heritage  from 
lower  grades  of  organization  as  their  progenitors.  It 
does  not  occur  to  the  Darwinists  to  regard  man  as  the 


LOWEST  VERTEBRATE  ANIMALS. 


255 


direct  offspring  of  the  present  apes  ;  neither  do  they 
infer  from  these  observations  on  the  Ascidian  larva  that 
vertebrate  animals  are  descended  from  the  Ascidians. 
Their  accordance  much  rather  forces  us  to  assume  an 
unknown  primordial  vertebrate  family,  springing  from 
some  branch  of  the  heterogeneous 
division  of  the  Annulosa.  From 
these  diverged  on  one  side  the  Tes- 
tacea,  who  might  perhaps  be  called 
mischanced  vertebrata,  and  on  the 
other  the  true  vertebrate  animals/* 

The  Amphioxus  which  lives  in  the 
sand  in  shallow  places  on  various 
coasts,  and  is  daily  caught  by  thou- 
sands at  Messina  for  example,  is  five 
or  six  centimetres  in  length,  and  is 
compressed  after  the  manner  of  a 
fish,  pointed  at  both  ends,  and  semi-  ^^^-  ^'-  fuu-r'-owu  Asddian. 
transparent  whilst  alive.  It  possesses  no  trace  of  limbs, 
at  the  posterior  end  only  a  pair  of  minute  membranous 
margins,  the  indication  of  dorsal  and  caudal  fins,  and  is 
so  simple  in  its  internal  structure  that  it  is  usually, 
though  inaccurately,  termed  a  fish.  Its  skeleton  is 
limited  to  the  noto-chord,  and  some  minute  cartilaginous 
rods  at  the  mouth  and  gills.  It  has  no  brain,  and, 
except  a  small  ciliated  sac,  perhaps  to  be  interpreted  as 
an  olfactory  organ,  no  sensory  apparatus  ;  the  heart  is 
tubular.  And  thus  between  the  lancelet  and  other 
true  fishes  there  exists  so  wide  a  difference  that  the 
possibility  remains  open  that  the  fishes  passed  through 
some  other  course  of  developm.ent  than  phases  like 
that  of  the  Amphioxus. 


256  THE   DOCTRINE  OF   DESCENT. 

Our  knowledge  of  the  genealogy  of  the  fishes  may  be 
laid  down  in  the  following  diagram  : — 

Dipnoi. 

Teleootci. 


Ganoids. 
Elasmobranchii. 


Marsipobranchii. 

The  Marsipobranchii  (CyclostomI),  it  is  true,  exhibit 
important  peculiarities,  such  as  deficiency  of  limbs,  entire 
absence  of  bony  plates  or  scales  on  the  integument ;  but 
the  brain,  heart,  and  vertebral  column  (which,  although 
persistently  cartilaginous,  is  far  superior  to  that  of  the 
Amphioxus),  show  their  direct  connection  with  the  fishes. 
Fossil  remains  of  these  animals,  universally  known  in 
the  genus  lamprey  (Petromyzon),  are  not  forthcoming, 
and,  at  the  most,  only  their  horny  teeth  could  have  been 
preserved. 

After  these  manifest  gaps  in  our  knowledge,  the  suc- 
ceeding orders  of  fishes  present  themselves  in  a  connec- 
tion all  the  more  conspicuous.  The  starting-point  is 
formed  by  the  Elasmobranchii,  to  which  belong  the  true 
chimeras,  sharks,  and  rays.  Brain  and  gills  testify  their 
kindred  with  the  Marsipobranchii.  In  the  construction 
of  the  cranium,  facial  bones,  pectoral  and  pelvic  arches, 
and  the  anterior  extremities,  heart  and  intestine,  they 
exhibit  forms  to  which,  as   Gegenbaur  has  shown  in  his 


PEDIGREE  OF  FISHES.  257 

well-known  observations,  the  homologous  parts  of  the 
Ganoids  are  related  either  as  progressive  developments 
or  as  reductions.  Huxley  has  also  prepared  the  way  for 
a  correct  apprehension  of  these  relations.  To  be  fully 
convinced  of  this,  detailed  study  is  certainly  requisite ; 
for  in  its  absence  it  is  impossible  to  imagine,  how  in  the 
Elasmobranchii  the  true  branchial  apparatus  is  wanting, 
and  how  the  cartilaginous  arch,  which,  in  them,  ivjplaces 
the  gills,  is  applied  in  the  Ganoids,  partly  as  the  palate, 
and  partly  as  the  attachment  for  the  true  lower  jaw,  while 
the  internal  gills  of  the  former,  become  the  external 
gills  of  the  latter  ;  how  in  the  skeleton  of  the  anterior 
extremities,  a  gradual  simplification  may  be  exhibited, 
step  by  step,  from  the  sharks  and  rays  to  the  Ganoids, 
and  especially  the  sturgeon, — a  process  of  which  the  two 
extremes  are  reached  in  the  Teleostei  on  the  one  side 
and  the  higher  Vertebrata  on  the  other — in  the  latter 
in  the  multiform  perfection  of  the  arm  and  hand. 

Of  the  Ganoids  only  scattered  remnants  survive,  the 
sturgeon  family  and  some  few  American  and  African 
genera,  of  which,  as  Riitimeyer  says,  a  flight  into  fresh 
water  has  been  the  salvation.  They  just  suffice  to 
explain  the  relation  of  this  once  extraordinarily  exten- 
sive group,  to  the  Elasmobranchii  as  well  as  the  Teleostei. 

In  the  Teleostei,  the  metamorphosis  of  the  organ- 
ization of  the  Elasmobranchii  initiated  in  the  Ganoids, 
is  carried  yet  further.  It  is  only  with  great  qualifica- 
tion that  they  can  be  termed  "  more  highly  developed," 
in  the  skeleton  perhaps,  to  which  older  zoologists  attri- 
buted too  much  importance.  Brain,  heart,  the  form  of 
the  extremities,  and  the  reproductive  system,  are  indeed 
distinct  developments  which,  in  combination  with  the 
external  shape  and  integuments,  have  exhibited  great 


2  53  THE   DOCTRINE   OF   DESCENT. 

powers  of  adaptation,  but  have  not  proved  capable  of 
any  further  development.  Comparative  anatomy  has 
vainly  spent  much  labour  in  attempting  to  trace  the 
condition  of  the  higher  animals  from  the  spec"al  organ- 
ization of  the  Teleostei,  or  to  explain  the  peculiarities 
of  the  Teleostei  from  above  downwards.  It  was  labour 
lost,  for  the  solution  is  to  be  reached  only  by  the 
method  indicated  in  the  derivation  of  the  Teleostei, 
through  the  Ganoids,  from  the  shark-like  fishes. 

Hence,  at  the  present  period,  a  development  is  con- 
cluded with  the  Teleostei,  and  we  must  look  to  another 
grade  for  the  transition  from  the  fishes  to  the  amphibians. 
We  find  one  in  the  order  of  the  mud-fishes  (Dipnoi), 
scantily  represented  by  only  few  species  (Lepidosiren 
Protopterus).  These  fish-like  animals,  living  in  American 
and  African  rivers  which  dry  up  in  the  hot  season  of 
the  year,  are  fish  by  right  of  their  skeleton  and  scales, 
and  some  other  characteristics ;  the  skull,  however, 
almost  resembles  that  of  an  amphibian,  and  they  also 
provisionally  use  their  swim-bladders  as  lungs  ;  and  by 
thus  breathing  alternately  water  and  air,  they  set  before 
us  the  transition  of  the  gill-breathing  larvae  of  the 
amphibians  to  the  phase  of  air-breathing.  Of  the  true 
fishes  at  the  present  time,  they  most  nearly  approach 
the  family  of  the  Crossopterygii,  represented  by  the 
African  Polypterus  ;  and  the  discovery  of  a  very  re- 
markable Australian  fish,  the  Ceratodus,  confirms  this 
affinity. 

Through  forms  thus  resembling  the  Dipnoi,  the 
advance  from  the  fishes  to  the  amphibians  was  probably 
accomplished.  But,  as  a  scientific  friend,  profoundly 
versed  in  the  history  of  development,  has  pointed  out 
to  me, — supporting  his  remark  on  the  comparison  of  the 


TRANSITION  TO  THE  AMPHIBL\NS.  259 

re«5piratory  organs  of  the  IMarsipobranchii  with  those 
of  the  amphibians, — it  is  possible  that  frogs  and  sala- 
manders may  be  directly  descended  from  beings  closely 
analogous  to  the  division  of  the  Marsipobranchii  termed 
Myxine.  It  is  to  be  hoped  that  this  highly  interesting 
observation  may  soon  be  made  public.  We  gather 
from  the  general  Ontogenesis  of  the  amphibians,  that 
the  tailed  forms  are  the  most  ancient.  This  is  also 
the  case  with  the  oldest  amphibian-like  animals,  the 
Labyrinthodonts.  From  their  remains  (Archegosaurus 
and  others),  chiefly  contained  in  the  Carboniferous  for- 
mation, we  have  learnt  that  they  had  incomplete  limbs 
or  none,  that  their  ventral  side  was  partially  provided 
with  bony  plates,  the  vertebral  column  fish-like,  and 
that  their  skull,  with  some  of  the  characters  of  the 
present  amphibians,  combined  others  which  remind  us 
partly  of  certain  bony  Ganoids,  and  partly  of  the 
reptiles  which  subsequently  appeared.  Now  if  in  the 
singularly  elongated  snake-like  Coecilia,  which  is  how- 
ever without  tail  or  limbs,  some  peculiarities  of  the 
skull  of  the  Labyrinthodont  appear  again,  we  must 
own  our  utter  ignorance  as  to  the  actual  progenitors  of 
this,  as  well  as  of  the  two  other  living  orders  of  the 
Coecilia  and  the  Batrachians.  Here,  therefore,  we  are, 
as  we  have  said,  thrown  entirely  on  the  evolutionary 
history  of  the  individual.  By  what  right  we  may 
frame  a  picture  with  great  probability  approaching  the 
truth,  the  reader  may  have  gathered  from  our  previous 
chapters. 

Among    the    tailed   amphibians,  it   is   not    only  in 
Ontogenesis  that  we  see  the  passage  from  gill  to  lung- 
breathing  ;    the  systematic  series  from  the  proteus  to 
the  triton   and  the   salamander,  likewise  exhibits  this 
18 


26o 


THE   DOCTRINE   OF   DESCENT, 


physiological  ascent,  linked  with  various  morphological 
transformations,  which  may  similarly  be  shown  between 
the  ancient  and  modern  specimens  of  the  Labyrintho- 
donts.  The  Batrachians,  indeed,  rise  higher  in  develop- 
ment than  the  Coecilia  ;  but,  as  the  friend  above  men- 
tioned informs  me,  they  more  nearly  approach  the 
Myxine  in  the  construction  of  the  internal  gills  of  their 
larva.  We  shall  obtain  a  general  view  of  the  reptiles 
by  means  of  the  appended  diagram,  in  which  we  shall 
avoid  any  minute  systematic  designations. 


« 

.S 

d 

M 

ja 

s 

"C 

C 

>-» 

o 

y 
1 

1 

c 

o 

_52 

1 

.a 

1 

U 

6 

Present  Age 

Diluvium   

t 
t 

t 
t 

t 
t 

Tertiary  Period    

Chalk 

t 
f 

t 

t 
t 

t 
t 

t 
t 
t 

Oolite 

t 
t 

t 
t 

Trias 

t 

Dyas 

Coal  

I 


PEDIGREE   OF   REPTILES.  261 

The  class  presents  a  very  comprehenyive  picture, 
although  only  four  orders  now  exist,  of  which  two,  the 
li:iards  and  the  snakes,  are  scarcely  to  be  separated. 
That  the  snakes,  which  first  appear  in  the  Tertiary 
period,  are  a  direct  offshoot  from  the  lizards,  is  reduced 
to  a  certainty  by  comparative  anatomy  and  the  history  of 
development.  In  the  various  families  of  lizards  we  sec 
the  absence  of  feet  occurring  in  conjunction  with  the 
elongation  of  the  body  and  the  multiplication  of  the 
vertebrae ;  and  the  modifications  peculiar  to  the  skull  of 
the  "  true  "  snakes  are  likewise  represented  in  the  syste- 
matic series  in  every  gradation,  beginning  with  the  skull 
of  the  true  lizard.  We  cannot  specify  the  fossil  genera 
in  which  the  transformation  was  initiated  ;  but  in  this 
case  a  doubt  would  be  only  a  capricious  denial.  It  is 
otherwise  with  the  remaining  orders,  which  in  the  be- 
ginnings, hitherto  accessible  to  us,  exhibit  diversities  so 
decidedly  marked,  that  in  none  has  it  been  possible  to 
trace  a  direct  descent  from  any  known  member  of 
another.  Prof  Huxley,  a  great  authority  on  the  anatomy 
of  these  animals,  says  on  this  subject  as  follows  : — 

"  If  we  ask,  in  what  manner  the  earliest  representatives 
of  these  orders  are  distinguished  from  their  living  or 
latest  known  representatives,  we  shall  find,  in  all  cases, 
that  the  amount  of  difference  in  itself  is  remarkably 
small  in  comparison  with  the  length  of  time  during 
which  the  order  has  existed.  So  far  as  I  know,  there  is  no 
fact  to  show  that  the  later  Plesiosauria,  or  Ichthyosauria, 
exhibit  an  advance  upon  the  earlier  members  of  the 
group.  It  is  not  clear  that  the  Dinosauria  of  the  weal- 
den  and  of  the  Cretaceous  formations  are  more  highly 
organized  than  those  of  the  Trias ;  and  even  where   a 


262  THE  DOCTRINE  OF  DESCENT. 

differentiation  of  structure  is  to  be  observed,  as  in  the, 
Lacertilia,  or  Crocodilia,  it  goes  no  further  than  a  modi- 
fication of  the  form  of  the  articular  surfaces  of  the  verte- 
brae, or  of  the  degree  to  which  the  internal  nasal  aper- 
tures are  surrounded  by  bone.  The  osteological  differ- 
ences, which  alone  are  exhibited  by  fossil  remains,  have 
doubtless  been  accompanied  by  many  changes  in  the 
organization  of  the  destructible  parts  of  the  body ;  but 
everything  tends  to  show  that  the  amount  of  change  in 
the  organization  of  reptiles  since  their  first  known  ap- 
pearance upon  the  earth,  is  not  great  in  itself ;  and  is 
wholly  insignificant,  if  we  take  into  consideration  the 
lapse  of  time,  and  the  changes  of  the  surface  of  the 
globe,  which  are  represented  by  the  Mesozoic  and  Ter- 
tiary formations. 

"  From  the  point  of  view  of  the  evolution  hypothesis, 
it  is  necessary  to  suppose  that  the  Reptilia  have  all 
sprung  from  a  common  stock,  and  I  see  no  justification 
for  the  supposition  that  the  rapidity  of  their  divergence 
from  this  stock  was  greater  before  the  epoch  of  the 
Trias  than  it  has  been  since.  Consequently,  seeing 
that  the  approximation  of  the  oldest  known  representa- 
tives of  the  diff"erent  orders  is  so  slight,  reptiles  must 
have  lived  before  the  Trias  for  a  length  of  time,  com- 
pared with  which  that  which  has  elapsed  from  the 
Triassic  epoch  until  now  is  small — in  other  words,  the 
commencement  of  the  existence  of  reptiles  must  be 
sought  in  a  remote  palaeozoic  epoch." 

Comparison  thus  points  us  back  to  ages  which  afford 
no  record  of  the  actual  derivation  of  this  class.  Even 
the  Ichthyosauria  and  Plesiosauria,  so  frequently  men- 
tioned in  conjunction,  deviate  widely  from  one  another 


PEDIGREE   OF   VERTEBRATE  ANIMALS.  263 

in  very  essential  characters,  which  refer  their  supposed 
common  origin  to  a  remote  period.  We  will  mention 
only  the  fin-like  extremities  of  the  former,  which  are 
of  an  obviously  piscine  type.  We  are  thus  thrown 
l)ack  vaguely  on  such  mixed  forms  as  may  have  been 
analogous  to  the  Labyrinthodont  ;  nay,  the  ques- 
tion arises  whether  the  Ichthyosauria  alone,  or  per- 
haps the  Plesiosauria  with  them,  did  not  diverge 
from  the  fishes  independently  of  the  other  branches  of 
the  reptile  family ;  an  eventuality  which  is  taken  into 
account  in  the  pedigree  at  p.  250.  A  certain  resem- 
blance with  the  skull  of  the  tortoises  (Chelonia)  is 
exhibited  by  that  of  the  Dicynodonta.  In  them  also 
the  jaws;  as  appears  from  their  shape,  were  manifestly 
cased  in  horny  sheaths  ;  but  at  the  same  time  the  upper 
jaw  contained  two  huge  tusks,  and  it  is  scarcely  possible 
to  imagine  a  direct  transition  from  the  Dicynodonta,  ap- 
pearing in  the  Trias,  to  the  more  recent  tortoise.  In  some 
particulars  of  the  skull,  as  well  as  in  the  situation  of  the 
posterior  nasal  apertures,  the  forms  of  older  crocodiles 
exhibit  an  aflfinity  with  the  lizards,  from  the  older  and 
unknown  forms  of  which  they  probably  branched  off. 
The  winged  saurians,  or  Pterodactyles,  may  also  be  a 
branch  of  the  lizards.  They  have  gained  by  adaptation 
several  characters,  such  as  the  shape  and  lightness  ol 
head,  the  length,  slenderness,  and  pneumatic  character 
of  the  tubular  bones,  which  they  share  with  the  birds. 
But  it  is  not  in  them,  but  in  the  division  comprising 
neveral  families  which  Huxley  terms  Ornithoscelidai, 
cr  reptiles  with  the  legs  of  a  bird,  that  we  must  look  for 
the  actual  progenitors  of  the  birds.  For  among  them 
one  of  the  most  important  characters  of  the  birds  is,  in 


264  THE  DOCTRINE  OF  DESCENT. 

some  genera,  in  course  of  preparation,  so  that  in  the 
full-grown  animal  its  origin  may  still  be  recognized  ; 
in  others,  as  the  genus  Campsognathus,  it  is  accom- 
plished. We  allude  to  the  peculiarity  already  discussed 
in  p.  10,  that  the  upper  portion  of  the  tarsus  is  anchy- 
losed  with  the  tibia,  the  lower  with  the  metatarsus,  and 
that  the  ankle-joint  is  hence  inserted  into  the  tarsus. 

All  existing  reptiles  are  sharply  distinguished  from 
the  Amphibians  and  Fishes  by  several  phenomena  ac- 
companying their  development.  They  possess  two 
organs  enveloping  the  embryo ;  the  amnion,  which  is 
essentially  a  protecting  sheath,  and  the  allantois,  bv 
which  the  foetal  circulation,  nutrition,  and  respiration  is 
regulated  and  carried  on.  In  the  Batrachians  we  find 
indications  at  least  of  the  allantois,  and  must  suppose 
that  the  greater  part  of  the  fossil  reptiles  had  already 
adopted  this  advance  in  general  organization.  It  implies 
an  advance,  inasmuch  as  animals  developed  by  the  aid 
of  the  amnion  and  allantois  make  further  progress  during 
the  embryonic  phase  than  is  the  case  with  the  inferior 
Vertebrata,  and  that  they  hence  leave  the  egg  with  greater 
powers  of  resistance.  We  must  ascribe  the  adoption  of 
the  amnion  and  allantois  to  remote  periods  of  amphibian 
and  reptile  development,  for  the  additional  reason  that 
the  possession  of  their  embryonic  sheaths  and  organs 
is  shared  by  the  birds  which  are  descended  from  true 
reptiles,  and  by  the  mammals  which  cannot  be  descended 
from  true  reptiles. 

The  birds  are,  anatomically,  so  closely  allied  to  the 
reptiles,  that  Huxley,  who  has  carried  out  the  com- 
parison most  rigorously,  has  joined  the  two  classes  into  a 
greater  systematic  unit,  under  the  name  of  Sauropsida, 


PEDIGREE   OF   BIRDS.  265 

or  lizard-like  animals.  The  scale  of  a  lizard  and  a 
feather  seem  to  be  totally  different  things ;  but  in  their 
nrst  rudiments  they  are  completely  identical,  and  the 
feather  has  a  far  greater  analogy  with  the  scale,  than  with 
the  hair.  The  plumage,  which  seems  to  impress  a  spe- 
cific character  upon  the  bird,  is  therefore  to  be  traced 
from  the  formation  of  scales.  Of  the  internal  soft  organs, 
we  will  only  remark  upon  the  heart  and  lungs.  All  the 
older  geologists  placed  the  heart  of  the  bird  on  the  same 
level  with  that  of  the  mammal  and  of  man  ;  in  its  specific 
arrangements,  however,  it  is  only  to  be  interpreted  by 
the  heart  of  the  reptile,  and  the  wind-pipe  is  not  ramified 
as  in  the  mammal.  That  the  reptiles  exhibit  a  gradual 
transition  to  the  leg  of  the  bird,  has  been  repeatedly 
pointed  out.  The  pelvis  of  the  bird,  which  is  remarkable 
for  the  length  of  the  pubis  and  ischium,  and  is  open  in 
front,  likewise  represents  only  a  slight  advance  in  develop- 
ment upon  the  pelvic  structure  already  shown  in  several 
of  the  Ornithoscelidae.  Thus  Huxley  says  with  reference 
to  the  ischium  of  the  Hypsilophodae,  that  "  the  remark- 
able slenderness  and  prolongation  of  the  ischium  give  it 
a  wonderfully  ornithic  character."  Finally,  in  the  skull, 
peculiarities  possessed  by  the  bird  in  contrast  with  the 
mammal,  such  as  the  simple  condyle  of  the  occiput,  the 
quadrate  bone,  the  cochlea  of  the  auditory  labyrinth,  the 
composition  of  the  lower  jaw,  its  articulation  with  the 
skull  by  the  intervention  of  the  quadrate  bone,  &c.,  are 
not  specific  characters  of  the  bird  alone,  but  of  reptiles  in 
general.  This  similarity  of  type  in  reptiles  and  in  birds 
's  perfectly  manifest  from  the  comparison  of  living  birds 
with  living  reptiles.  But  the  proof  that  the  bird  is 
derived  from  the  reptile  is  rendered  unimpeachable  by 


266 


THE   DOCTRINE   OF   DESCENT. 


the  discoveries,  scanty  as  they  are,  of  fossil  intermediate 
forms.  The  pelvis  and  leg  of  the  Ornithoscelidas  have 
already  been  discussed.  But  in  the 
slates  of  Solnhofen  we  have  more- 
over become  acquainted  with  the 
Archaeopteryx,  a  bird  unfortu- 
nately mutilated  and  in  many 
ways  damaged  by  pressure  (Fig. 
25,  impression  of  the  tail  of  the 
Archaeopteryx  Macrurus,  Ow),  but 
exhibiting  a  very  valuable  and 
interesting  intermediate  stage  be- 
tween the  tail  of  a  reptile  and  a 
bird.  Among  existing  birds,  the 
Nandu,  or  American  ostrich  (Rhea), 
alone  possesses  numerous  separate 
caudal  vertebrae  ;  but  the  tail  of 
this  bird  projects  so  Kttle,  that  it 
in  no  way  recalls  the  tail  of  a  lizard. 
Now  the  Archaeopteryx  exhibits  a 
long  tail,  bordered  by  two  rows 
^'^'  ^^"  of    stiff    feathers,    of    which     the 

impression  remains  in  extraordinary  preservation.  The 
skull  of  this  valuable  specimen,  now  in  the  British 
Museum,  is  so  much  injured,  that  no  idea  can  be  framed 
of  its  construction.  It  is  impossible  to  decide  whether 
the  jaws  bore  teeth.  The  example  of  the  tortoises 
shows  that  within  the  reptile  type  the  formation  of  teeth 
was  replaced  by  horny  sheaths,  without  a  correlated 
development  of  the  power  of  flight ;  the  Pterodactyles, 
on  the  other  hand,  combine  with  the  power  of  flight  a 
light  head,  provided   nevertheless  with  numerous  teeth. 


PEDIGREE  OF   BIRDS.  267 

Tb.e  obscurity  which  surrounded  these  parts  of  the  old 
antediluvian  birds  has  been  cleared  up  by  a  discovery  by 
the  American  naturalist,  Marsh.  He  found  in  the  upper 
Chalk  of  Kansas  the  remains  of  two  genera  of  birds, 
which  by  their  bi-concave  vertebrae  remind  us  of  the 
characteristics  of  the  ancient  reptiles,  and  by  this  alone 
present  extremely  valuable  intermediate  stages,  but 
which,  moreover,  bore  teeth  in  both  jaws.  These  teeth 
are  small  and  sharp,  and  were  so  numerous  that  in  the 
lower  jaw  of  the  animal  named  Ichthyornis  dispar, 
twenty  might  be  counted  on  each  side. 

Thus  we  are  now  quite  clear  as  to  the  kinship  of  the 
bird.  It  is  a  reptile  adapted  to  aerial  life,  and  those 
birds  which  we  see  more  estranged  from  flight  have 
acquired  the  characters  correlated  with  more  or  less 
incapacity  for  flight  only  by  means  of  retrogression.  It 
fares  the  worse  with  the  internal  arrangement  of  this 
class  of  animals.  Partly  from  their  geographical  distri- 
bution, partly  from  anatomical  indications,  especially  of 
the  skull,  it  may  be  inferred  that  the  ostrich-like  birds 
are  not,  in  virtue  of  their  strength  of  leg  and  adeptness 
in  running,  the  youngest  members  of  their  class  and  the 
most  nearly  allied  to  the  mammals,  but  that  they  are 
the  oldest  of  those  now  living.  The  nature  of  the 
imperfection  of  their  wings  shows,  as  we  have  said,  that 
they  are  in  a  state  of  arrest  or  retrogression.  Beyond 
this  general  experience  it  is  impossible  to  go.  If  we 
contemplate  the  bird  as  a  fl3'ing  animal,  those  of  course 
rank  highest  which  have  learnt  to  fly  the  best.  This 
palm  avowedly  accrues  to  the  birds  of  prey  as  a  whole, 
although  other  orders  are  not  deficient  in  pre-eminent 
flyers.     Brchm    and   others    hold    the  parrots,    because 


268  THE  DOCTRINE  OF   DESCENT. 

of  their  docility,  to  be  the  highest  birds.  But  all  this 
is  arbitrary,  and  can  only  accidentally  correspond  with 
the  true  and  unknown  ramification  of  the  ornithic  branch 
in  the  pedigree  of  the  Vertebrata. 

The  most  ancient  known  remains  of  the  Mammalia 
are  found  in  the  Trias.     They  occur  somewhat  more 
frequently  in  the  central  Mesozoic  strata,  and  they  all 
belong  to   Marsupial  animals.     Now  as  Marsupials,  in 
comparison  with  the  inferior  classes  of  vertebrate  ani- 
mals from  which  they  must  be  derived,  are  very  highly 
developed,  and    as  in    the    Monotremata   (Duck-mole, 
Ornithorhyncus,  and  Porcupine  ant-eater.  Echidna,)  we 
possess   mammals   which   are    manifestly   far    beneath 
the  Marsupials,  we  are  referred  entirely  to  conjecture 
and  inference  for  the  origin   of  the  mammals.     These 
point  to   amphibian-like  beings,   in  which   certain   pe- 
culiarities of  the  mammalian  skull,  such  as  the  double 
condyle   of    the   occiput,   were    prefigured,   and   which 
by   the   formation''  of    the    amnios   and    allantois    ap- 
proached  the   true  reptiles.     These  progenitors  of  the 
Mammalia  are  not,  however,  represented  in  any  order 
of  reptiles   or  amphibians   now  extant.     The   pedigree 
(p.  269)  in  which  we  have  grouped  the  more  accurately 
known  fossil  Mammalia  with  those  now  living,  contains 
considerable   gaps,    and    rests  in   a  great   measure   on 
hypothesis,  but  it  gives,  nevertheless,  with  approximate 
probability  a  correct  representation  of  the  consanguinity 
of  the  orders,  and  in  comparison  with  the  system  as  it 
was  constructed  in  the  school-books  prior  to  the  revival 
of  the  doctrine  of  Descent,  it  must  be  esteemed  a  great 
and  suggestive  advance. 


PEDIGREE   OF   MAMMALS. 


26g 


270  THE  DOCTRINE   OF   DESCENT 

As  regards  the  structure  of  their  skull,  the  constitution 
of  the  pectoral  arch,  and  their  persistence  in  the  phase 
(embryonic  in  other  mammals)  in  which  the  rectum 
and  the  urinary  and  genital  ducts  open  into  a  single 
cloaca,  the  Monotremata  (Ornithorhynchus,  Echidna), 
limited  to  Australia  and  Tasmania,  are  the  lowest  mem.- 
bers  of  their  class,  and  must  be  considered  as  remnants 
of  a  division  reaching  from  indeterminable  past  ages 
down  to  the  present  time.  It  may  be  presumed  that 
the  Marsupials  were  developed  from  an  analogous  grade. 
Their  powers  of  adaptation  have  been  chiefly  testified 
in  Australia,  where  the  subdivisions  of  the  order,  usually 
designated  as  families,  are,  in  dentition  and  habits  of  life, 
developed  in  a  manner  analogous  to  several  of  those 
orders  which  appear  on  the  second  great  scene  of  mam- 
malian development,  namely,  the  Northern  hemisphere. 

Far  advanced  beyond  the  Monotremata  as  to  skeleton, 
they  remain  on  a  low  grade  with  respect  to  the  repro- 
ductive system,  and  are  implacental,  like  the  Monotre- 
mata. That  is  to  say,  the  embryonic  blood-vessels  do  not 
enter  into  those  close  relations  with  the  blood-vessels  of 
the  maternal  ovary,  by  which  the  more  perfect  develop- 
ment of  other  mammals  within  the  mother's  womb  is 
effected.  This  character  and  the  correlative  formation  of 
the  pouch  in  which  to  carry  the  immaturely  born  off- 
spring, bind  together  the  various  families  of  Marsupials, 
which  deviate  from  one  another  like  other  orders. 

With  the  exception,  therefore,  of  the  two  orders  named, 
m  all  mammals  the  embryo  is  attached  to  the  maternal 
organism  by  the  so-called  placenta.  The  blood-vessels 
of  the  developing  offspring  which  reach  the  wall  of  the 
uterus  by  the   intervention   of  the  allantois,  form  coils 


PEDIGREE  OF   MAMMALS.  27 1 

and  loops,  between  which  grow  similar  offshoots  and 
appendages  of  the  blood-vessels  of  the  ovary,  so  that 
through  the  walls  of  the  contiguous  blood-vessels  an 
abundant  exchange  of  fluids  takes  place  between  the 
two,  and  therewith  a  prolonged  nutrition  and  a  further 
and  more  complete  development  of  the  foetus.  The 
higher  character  of  the  placental  mammals,  usually 
plainly  evinced  by  their  anatomical  relations,  is  thus 
based  on  the  existence  of  the  placental  mass.  All  inter- 
mediate grades  are,  however,  wanting  which  would 
entitle  us  to  infer  with  certainty  the  direct  transition 
from  implacental  to  placental  mammals.  The  Edentata, 
(Bruta),  manifestly  the  lowest  of  placental  mammals, 
are  so  devoid  of  any  nearer  morphological  relations 
with  the  Marsupials,  that  we  must  needs  be  content  to 
assume  generally,  on  these  indications,  supported  by 
geographical  distribution  and  geology,  that  they  repre- 
sent a  very  ancient  branch  of  the  placental  mammals. 
As  we  saw  in  the  tenth  chapter,  they  are  scattered 
remnants  which  can  only  by  compulsion  be  united 
into  a  single  order.  Sloths,  armadilloes,  ant-eaters, 
differ  from  one  another  at  least  as  much  as  rodents, 
insectivora,  and  bats.  The  doctrine  of  Descent  is  not 
discredited  because  it  is  unable  to  account  for  these 
fragments  of  bygone  animal  life,  but  in  the  absence 
of  data  it  is  for  the  time  in  presence  of  an  impos- 
sibility. 

To  ascertain  the  relationships  of  other  orders,  the 
modern  systematizers,  and  also  the  supporters  of  the 
system  of  Descent,  have  thought  fit  to  lay  great  stress 
on  the  presence  or  absence  of  the  so-called  decidua. 
This  requires  a   short  explanation.     In  many  orders  of 


2^2  THE  DOCTRINE  OF  DESCENT. 

mammals,  the  vascular  processes  and  vilii  of  the  wall 
of  the  ovary  become  so  closely  connected  with  the  foetal 
portion  of  the  placenta,  that  at  birth  the  entire  mem- 
branous coating  of  the  ovary  is  detached  and  thrown  out 
with  it.  In  others,  the  vascular  villi  are  not  so  closely 
adherent ;  they  yield  without  important  lacerations,  and 
hence  no  deciduous  membrane  (Membrana  decidua)  is 
ejected.  Now,  as  it  appears  to  me,  the  specific  conditions 
of  the  formation  of  the  decidua  have  been  far  too  little 
compared  to  justify  our  inferring  any  close  affinity  from 
the  mere  fact  that  portions  of  the  coating  of  the  ovary 
are  lost  in  parturition.  Much  rather  it  must  be  unre- 
servedly admitted  that  the  formation  of  decidua  might 
be  occasioned  by  subordinate  circumstances  of  the  most 
varied  kinds,  and  hence  in  orders  only  remotely  allied, 
or  allied  merely  as  placental  mammals.  We  therefore 
consider  the  decidua  to  be  a  subordinate  systematic 
feature  where  anatomical  and  morphological  reasons 
are  opposed  to  it. 

We  go  yet  further.  In  the  modern  system  the  form 
of  the  placenta  is  likewise  employed  in  the  grouping  of 
organisms.  If  among  the  Deciduata,  lemurs,  rodents, 
insect  ivora,  bats  and  monkeys,  are  classed  together  as 
orders  with  discoidal  placenta,  this  combination  is  cer- 
tainly supported  by  a  series  of  other  reasons,  and  it  is 
quite  probable  that  within  this  group  of  orders  the  form 
of  the  placenta  is  due  to  homology,  that  is  to  Descent 
But  when  beasts  of  prey,  elephants  and  the  Daman 
(Hyrax)  are  further  cited  as  orders  with  zonary  pla- 
centa, we  find  ourselves  in  the  same  position  as  when 
the  decidua  was  reckoned  decisive  as  to  the  closer 
affinity;  and  we  are  of  opinion  that  the  subordinate  form 


PEDIGREE  OF  MAMMALS. 


273 


of  the  placenta  might  similarly  arise  in  different  ways, 
just  as  it  has  been  variously  developed  in  the  well-sub- 
stantiated division  of  the  Ungulata.  To  corroborate  our 
view  by  example,  we  are  certainly  unable  to  make  any 
positive  statements  as  to  the  derivation  of  the  Probos- 
cidx.  It  is,  however^  none  the  less  certain  that  nothing 
positive  is  implied  by  the  customary  classification  by 
reason  of  their  zonary  placenta.  But  we  shall  more 
nearly  approach  the  truth  if  we  place  this  branch  of 
unknown  origin  typically  nearer  to  the  Ungulata  than 
to  the  beasts  of  prey.  If,  moreover,  as  non-deciduate 
mammals,  the  Cetacea  are  held  to  be  more  closely 
allied  to  the  Ungulata  than  to  the  Carnivora,  which 
are  deciduate, — in  our  eyes,  this  circumstance  is  not 
decisive,  as  more  important  reasons  argue  that  the 
Cetacea  were  first  developed  from  carnivorous  genera. 

In  our  exposition  of  the  geographical  distribution  of 
animals,  we   derived   instruction   from  Riitimeyer  with 

Horses. 


Hipparion. 


Anchitherium. 


I 
Palaeotheridae. 


Macrauchenidae. 


reference    to    the    relationships    of    the    Ungulata    in 
particular.     In   no  other   division    do   we  possess  such 


274 


THE   DOCTRINE   OF    DESCENT. 


abundant  fossil  material.  In  the  older  Tertiary  strata 
we  encounter  the  remains  of  two  Ungulate  families, 
the  Palaeotheridae  and  the  Anoplotheridae,  essentially 
distinguished  from,  one  another  by  their  dentition, 
and  forming  the  starting-points  of  the  groups  of  Un- 
gulates of  which  some  now  appear  so  greatly  isolated. 
The  root  to  which  these  two  families  lead  back  is  un- 
known ;  on  the  other  hand,  partly  from  the  direct 
comparison  of  these  genera  with  the  present  Ungulata, 
partly  from  numerous  intermediate  links  found  in  the 
Miocene,  Pliocene,  and  Diluvium,  it  appears  that,  in  the 
lapse  of  time,  the  separation  which  characterizes  the 
present  age  was  initiated,  and  the  seeming  isolation  was 
produced  by  the  extinction  of  the  intermediate  links.  It 
was  this  isolation  which  induced  the  older  systematizers 
to  institute  three  orders  of  Ungulata. 

The  special  pedigree  emanating  from  the  Palaeotheridae 
includes,  among  the  present  Ungulata,  the  horse,  tapir, 

and  rhinoceros.  The  transi- 
tion from  the  Palaeotherium 
to  the  horse  may  be  directly 
traced,  and  this,  moreover, 
in  the  two  most  important 
characters,  the  dentition  and 
the  feet.  In  the  Anchithe- 
rium  and  Hipparion,  the 
transformation  from  the  tri- 
dactyle  to  the  unidactyle 
Ungulate  is  accomplished  ; 
and  Riitimeyer's  brilliant  re- 
searches have  shown  how;  in 
the  milk  dentition  of  each  genus,  the  definitive  dentition 


Fig.  26.    Skeleton  of  the  foot, 
rium.    (H)  Hipparion.    (E)  Horse, 


PEDIGREE   OF    MAMMALS. 


275 


of  the  aboriginal  genus  is  repeated,  and  Philogenesis  is 
unequivocally  expressed  in  Ontogenesis.  The  Anchi- 
therium  is  a  three-toed  horse,  in  which,  however,  the 
middle  toe  has  already  undertaken  the  chief  task.  But 
in  the  Hipparion  the  two  side  toes  are  entirely  raised 
from  the  ground,  and  by  disuse  are  brought  to  the  con- 
dition of  arrest  which  is  completed  in  the  horse. 

In  the  constitution  of  the  molar  teeth  the  tapirs  have 
remained  most  faithful  to  the  ancestral  type.  The  cir- 
cumstance that  the  tapir  has  four  toes  in  front,  whereas 
the  Palaeotheridae  known  to  us,  have  three  shows,  how- 
ev^er,  that  the  genus  Palaeotherium  cannot  have  been 
the  ancestral  stock  of  the  tapirs.  For  the  supposition 
that  the  tapir  acquired  the  fourth  toe  is  contrary  to  all 
experience  respecting  the  formation  of  the  extremities. 
Rhinoceroses  are  also  four-toed  in  front,  and  their  close 
kindred  with  the  tapirs  is  testified  by  the  structure  of 
their  toes  and  a  series  of  details  in  the  skeleton. 

Hippopotami.       Pigs.  Tragulidae.         Deer.        Antelopes.        Oxen. 


Anoplotheridae. 

An  isolated  branch  of  the  Palaeotheridae  seems  to  be 
the  fossil  genus    Macrauchenidae,   which   combines   th«* 
19 


2/6  THE   DOCTRINE   OF  DESCENT. 

characteristics  of  the  horse  and  rhinoceros  with  those 
of  the  camel.  How  far  the  latter,  as  ruminants,  are 
directly  connected  with  the  Macrauchenidae,  or  whether 
the  form  of  their  skull,  approaching  that  of  the  horse, 
points  to  actual  homology,  it  is  for  the  present  impossible 
to  say. 

The  Anoplotheridae  are  likewise  distinguished  by  a 
sort  of  undifferentiated  dentition,  from  which  a  number 
of  specific  forms  might  deviate  in  different  directions. 
The  Tragulidoe  are  descended  from  them  in  a  direct 
line;  they  form  a  small  group  not  unlike  the  musk 
animals,  and  are  confined  to  South  Africa  and  Southern 
Asia.  As  chewing  the  cud,  they  are  more  nearly  allied 
*-o  the  other  typical  ruminants  with  which  we  are  ac- 
quainted; but,  on  the  other  hand,  they  occupy  an  inter- 
mediate position  towards  the  other  non-ruminants  of  the 
division,  of  which  the  whole  was  united  in  the  pre-historic 
world  through  the  Anoplotheridae.  The  Suidae,  or  pig- 
like animals,  were  very  profusely  represented  in  the 
Eocene  and  Miocene  periods.  From  a  side  branch  of 
their  predecessors,  reaching  up  to  the  Anoplotheridae,  are 
descended  the  river-horses,  or  hippopotami.  The  function 
of  ruminating  is,  as  we  know,  correlated  with  a  complex 
structure  of  the  stomach  as  well  as  a  peculiar  mechanism 
of  the  cesophagal  groove.  It  is  naturally  impossible  to 
determine  in  which  fossil  animals  these  arrangements 
originated  ;  yet  it  seems  to  have  occurred  at  a  very 
early  period.  Perhaps  the  more  highly  integrated  struc- 
ture of  some  non-ruminating  genera,  such  as  the  hippo- 
potamus and  the  peccary,  may  have  been  transmitted 
from  the  age  of  the  Anoplotheridae,  and  the  very  con- 
spicuous accordance  of  the  ruminating  Tragulidae  with 


PEDIGREE  OF   MAMMALS.  277 

the  Anoplotheridae  stamps  the  latter  with  tolerable 
certainty  as  ruminants. 

Disregarding  the  camels,  already  mentioned  as  of 
doubtful  origin,  the  typical  ruminants  separate  into  the 
deer-like  and  the  horned.  Through  the  hornless  musk 
animals,  the  deer  are  connected  with  the  Tragulidae  and 
the  older  genera.  The  giraffes  form  a  side  branch.  But 
although  the  Helladotherium,  nearly  allied  to  the  girafife 
and  at  one  time  inhabiting  the  Athenian  territory  in 
herds,  and  the  colossal  Sivatherium,  found  in  the  spurs  of 
the  Himalayas,  afibrd  some  clue  to  the  position  of  the 
giraffes,  so  entirely  isolated  in  the  present  world,  the 
details  of  their  derivation  still  remain  very  obscure. 

From  the  antelopes  to  the  closely  allied — in  fact, 
scarcely  separable  —  genera  of  goat  and  sheep,  and 
similarly  to  the  oxen,  the  systematic  as  well  as  the  palae- 
ontological  series,  and  likewise  the  ontogenetic  phases, 
present  transitions  undeniably  evincing  family  relation- 
ship. Besides  the  relations  of  the  milk  dentition  of  the 
filial  to  the  ancestral  genera,  which  Riitimeyer  has  also 
followed  minutely,  great  interest  attaches  to  the  gradual 
transformation  of  the  skull,  which  reaches  its  extreme  in 
the  oxen,  and  advances  from  the  antelope  and  sheep, 
through  Ovibos,  Bubalus  (buffalo),  Bison,  to  Bos  (ox). 
In  the  latter,  the  erect  position  of  the  frontal  bone  attains 
its  utmost  grade,  and  this  transformation  of  the  skull  of 
the  antelope  is  repeated  in  the  calf. 

The  usual  classification  of  the  Sirenia,  or  sea-cows,  with 
the  Cetacea,  was  decidedly  a  systematic  misconception, 
arising  from  one-sided  and,  moreover,  merely  superficial 
consideration  of  the  locomotive  organs.  All  other 
characteristic   indications — above   all,   the   structure  oi 


zyS  THE   DOCTRINE   OF    DESCENT. 

the  skull  and  the  nature  of  the  teeth — remove  them 
from  the  Cetacea  as  much  as  they  approximate  them 
to  the  Ungulata.  In  the  hippopotamus  we  have  a 
member  of  this  order  nearly  converted  into  an  aquatic 
animal.  We  must  think  of  the  Sirenia  as  originally 
emanating  from  some  unknown  genera,  which  probably 
branched  off  at  a  very  early  period. 

A  very  uncertain  position  is  occupied  by  the  Hyra- 
coidae,  now  represented  only  by  a  few  species  of  the 
genus  Hyrax.  To  say  that  their  characteristics  recall 
at  once  the  Ungulates,  the  Rodents,  and  the  Insectivora, 
affords  no  explanation.  Considering  the  great  impor- 
tance of  the  molar  teeth  in  deciding  derivation,  the 
chief  stress  should  perhaps  be  laid  on  their  similar- 
ity in  the  hyrax  and  the  rhinoceros,  and  we  hence 
regard  the  hyrax  as  an  offshoot  of  an  old  Ungulate 
family. 

With  respect  to  the  progenitors  of  the  Proboscidae,  we 
refrain  from  any  conjecture. 

Later  than  the  Graminivora,the  Carnivora,  and  espe- 
cially the  beasts  of  prey,  seem  to  have  appeared  on  the 
scene  of  arctic  animal  life.  Granting  the  possibility 
(and  it  is  scarcely  possible  to  do  otherwise)  that  pla- 
cental formations  may  have  originated  in  various  ways, 
the  possibility  likewise  exists  that  the  Carnivora,  and 
indeed  other  orders  too,  such  as  the  Rodents  especially, 
may  be  direct  descendants  of  carnivorous  Marsupials. 
The  oldest  beasts  of  prey  known  are  feline,  or  resemble 
the  Viverridae  and  hyenas.  Then  come  the  Canidae, 
and  latest  of  all  the  Ursidae.  In  skull,  dentition,  and 
extremities,  the  seals  and  walruses  (Pinnipedea)  consti- 
tute a  side  branch.     Although  there  can  be  no  idea  of 


PEDIGREE   OF   MAMMALS.  279 

any  special  affinity  between  the  otter  and  the  seal,  the 
comparison  of  the  two  will  aid  us  in  imagining  how  from 
true  beasts  of  prey  and  terrestrial  animals  the  strange 
figure  of  seals  and  walruses  must  have  proceeded. 

If  the  conjecture  already  propounded  should  be 
confirmed,  that  the  detachments  and  ejections  of 
the  placenta,  which  constitute  the  phenomena  of  the 
decidua,  assume  very  heterogenous  forms  in  groups 
belonging  to  the  same  family,  and  may  be  alike  in 
others  no  more  nearly  related,  the  Cetacea  would  be 
installed  in  our  pedigree  in  the  vicinity  of  the  beasts  of 
prey.  Between  a  lion  and  a  whale  an  angle  is  enclosed, 
containing  a  countless  multitude  of  intermediate  forms. 
But  we  must  always  bear  in  mind  that  our  business  is, 
not  to  bridge  over  the  chasms  between  the  present 
peripheral  ends  of  the  series  of  development  represent- 
ing the  extreme  forms,  but  to  discover  the  points  of 
derivation  and  attachment.  Fossil  whale-like  animals 
are  known  in  the  Tertiary  period,  such  as  the  Zeuglo- 
don  and  Squalodon.  The  remains  of  the  former  colossal 
genus  are  kept  in  good  preservation  at  Berlin,  where 
Johannes  Miiller  discovered  their  relations  to  both  seals 
and  whales.  The  dentition  is  seal-like;  in  the  skeleton 
there  is  much  similarity  with  the  whales ;  and  although 
the  Zeuglodons  must  have  been  preceded  by  a  great 
series  of  species,  and  followed  by  another  of  consider- 
able, if  not  equal,  length,  before  the  present  Cetacea 
proceeded  from  them,  a  development  of  this  sort  seems, 
nevertheless,  extremely  probable  and  natural.  By  their 
still  perfect  dentition  and  the  still  proportionate  dimen- 
sions of  the  skull,  the  Delphinoidae  are  the  oldest  mem- 
bers of  the  true   Cetacea.      They  were  joined  by  the 


28o  THE   DOCTRINE   OF   DESCENT. 

Sperm  whales  or  cachelots  (Physeteridae),  and  the  last 
members  are  the  right  whales  (Balasnidae).  This  is 
evinced  by  the  fact  that  the  whalebone  or  baleen  plates 
are  developed  only  after  the  rudimentary  teeth  have 
made  their  appearance  in  the  jaws  of  the  embryo,  a 
heritage  from  the  profusely  and  persistently  toothed 
ancestors. 

In  the  Lemuridae,  the  system  unites  the  heterogeneous 
remains  of  a  collection  of  animals  which,  by  reason  of 
their  prehensile  hind  feet  with  their  opposable  hallux, 
were  regarded  as  fellow-members  of  the  order  of 
"  true  apes."  The  connecting  link  is  not  their  anato- 
mical constitution — they  diverge  widely  in  the  form  of 
the  skull  and  in  dentition — but  rather  their  geographi- 
cal distribution,  restricted  to  Madagascar  and  a  few 
advanced  posts  of  Asia.  Undue  influence  has  also 
been  allowed,  certainly  very  unscientifically,  to  a  certain 
peculiar  outlandish  impression  which  they  make  upon 
the  observer.  The  constitution  of  their  skull  refers 
them  to  a  very  low  grade  in  the  scale  of  the  mammalia. 
If  we  view  them  as  a  whole,  they  exhibit  no  general 
relations  with  any  particular  order  of  mammals,  but, 
according  to  the  individual  genera,  point  to  those  orders 
which,  like  themselves,  possess  discoidal  placenta ;  the 
majority  of  reasons  favour  the  hypothesis  that  the 
Lemuridae  now  living  are  the  last  and  little  modified 
offshoots  of  a  division  of  mammals  at  one  time  far 
more  richly  developed,  and  that  Rodents,  Insectivora, 
Cheiroptera,  and  Apes,  are  twigs  of  this  great  branch. 

The  Rodents  are  particularly  interesting,  because,  in 
conjunction  with  stubborn  persistency  in  the  very  cha- 
racteristically  constituted    dentition,    accompanied    by 


TEDTGREE  OF   MAMMALS.  28 1 

several  peculiarities  of  skull,  they  manifest  the  most 
extraordinary  power  of  adaptation  to  arboreal  and 
steppe-life,  to  land  and  water.  The  Insectivora,  although 
not  nearly  so  rich  in  species,  offer  a  similar  spectacle  of 
adaptations  by  which  their  genera  have  become  almost 
repetitions  of  the  Rodents  ;  and  the  Cheiroptera  (bats), 
in  their  most  numerously  represented  division,  may  be 
regarded  as  a  side  branch  of  the  Insectivora,  if  they 
have  not  proceeded  directly  from  animals  resembling 
the  Lemuridae. 

In  what  geological  period  the  monkeys  were  evolved 
from  lemur-like  forms  we  do  not  know.  The  few  fossil 
monkeys  with  which  we  are  acquainted  belong  to  the 
higher  families  of  apes,  and  pre-suppose  a  long  series 
of  ancestors.  The  same  conjecture  is  forced  upon  us 
by  the  geographical  isolation  of  the  American  monkeys 
from  those  of  the  Old  World,  which  is  also  combined 
with  considerable  anatomical  differences,  although  it 
could  not  occur  to  zoologists  or  comparative  anatomists 
to  deny  their  close  systematic  affinity. 

The  relation  of  the  lower  to  the  higher  apes  requires 
further  discussion,  which  we  shall  combine  with  qui 
disquisition  on  the  relation  of  m.an  with  the  monkeys. 


282  THE  DOCTRINE   OF  DESCENT. 


XII. 

Man. 

When  Goethe  declares,  "We  are  eternally  in  contact 
with  problems.  Man  is  an  obscure  being  ;  he  knows 
little  of  the  world,  and  of  himself  least  of  all,"" — he 
almost  repeats  what  J.  J.  Rousseau  says  in  Emile," 
"  We  have  no  measure  for  this  huge  machine  (the 
world) ;  we  cannot  calculate  its  relations ;  we  know 
neither  its  primary  laws  nor  its  final  cause ;  we  do  not 
know  ourselves  ;  we  know  neither  our  nature  nor  our 
active  principle." 

Such  and  such-like  quotations  are  wont  to  be  made 
to  us  as  justifying  and  confirming  assertions  of  the 
narrowness  of  our  powers  of  understanding,  and  of  the 
limits  of  science.  But  in  Anthropology  we  cannot  pos- 
sibly attribute  any  greater  authority  to  the  worthy  J.  J. 
Rousseau  than  to  a  Father  of  the  Church ;  and  to  the 
Goethe,  whose  casual  utterances  are  transmitted  to  pos- 
terity by  Eckermann,  we  oppose  the  other  Goethe,  who 
in  the  fulness  of  youthful  vigour,  exclaims — 

Joy,  supreme  Creation  of  Nature,  feeling  the  power 

All  sublimest  thoughts,  which  lifted  her  as  she  made  thee, 

In  thyself  to  re-echo * 

and  who  conceives  the  most  beautiful  organization,  as  he 

•  Freue  dich,  hochstes  Geschopf  der  Natur,  du  f  Uhlest  dich  fahig 
Ihr  den  hochstcn  Gedanken,  zu  dem  sie  schaffend  sich  aufschwang, 
Nachzudenken *> 


THE   DOCTRINE  OF   DESCENT.  283 

designates  man,   to  be  in    perfect  harmony  with  these 
subHmest  thoughts. 

Our  previous  reflections  and  deductions  would  lack 
their  conclusion  were  man  to  be  excluded, — could  not 
and  must  not  all  that  is  said  of  the  genesis  and  connec* 
tion  of  animal  being,  be  directly  applicable  to  the  know- 
ledge of  his  nature  also.  The  repugnance  to  the  doctrine 
of  Descent,  the  doubt  with  regard  to  it,  the  indignation 
lavished  upon  it,  are  all  concentrated  on  its  applicability 
and  application  to  man  ;  and  if  the  body  be  perforce 
abandoned  to  us,  the  mental  sphere  of  man  is  at  least 
to  remain  inscrutable,  a  noli  tangere  to  the  investigation 
of  nature.  A  few  years  ago,  it  was  a  consolation  to  the 
opponents  of  the  doctrine  of  Descent  that  Darwin  had 
not  directly  pronounced  himself  with  respect  to  man. 
Anger  was  vented  on  his  adherents,  who  had  out- 
darwined  Darwin.  To  this  was  added  the  unfortunate 
misapprehension  that  the  champions  of  the  doctrine  of 
Descent  made  the  human  race  proceed  from  the  en^ 
noblement  of  the  orang,  chimpanzee,  or  gorilla — in  short, 
from  extant  apes. 

But  from  the  first  appearance  of  the  Darwinian  doc- 
trine, every  moderately  logical  thinker  must  have  re- 
garded man  as  similarly  modifiable,  and  as  the  result  of 
the  mutability  of  species  ;  and  Darwin  has  now  told  us, 
in  his  work  on  the  "  Descent  of  Man,"  why  he  did  not 
enunciate  this  self-evident  inference  in  his  first  book  ; 
he  did  not  wish  thereby  to  strengthen  and  provoke  pre- 
judice against  his  view.  Knowing  human  weakness,  he 
withheld  the  conclusion.  "  It  seemed  to  me  sufficient," 
he  says,  "  in  the  first  edition  of  my  '  Origin  of  Species,* 
that  by  this  work  '  light  would  be  thrown  on  the  origin 


284  THE  DOCTRINE  OF   DESCENT. 

of  man  and  his  history,'  and  this  implies  that  man  must 
be  included  with  other  organic  beings  in  any  general 
conclusion  respecting  the  manner  of  his  appearance  on 
this  earth." 

Nay,  Darwin  himself  has  now  gone  further,  and,  to 
the  terror  of  all  who  can  scarce  imagine  man  except  as 
created  shaven  and  armed  with  a  book  on  etiquette,  he 
has  sketched  a  certainly  not  flattering,  and  perhaps  in 
many  points  not  correct,  portrait  of  our  presumptive 
ancestors  in  the  phase  of  dawning  humanity. 

Before  we  seriously  discuss  this  serious  subject,  we  will 
take  leave  to  quote  a  more  superficial  verdict  given  by 
a  clever  essayist.*'  "  Let  us  suppose,  merely  as  a  joke, 
that  Nature,  which  we  see  everywhere  advancing  from 
the  most  simple  to  the  complex,  from  the  lower  to  the 
higher,  had  not  suddenly  waived  this  law  in  the  presence 
of  man  ;  that  she  had  not  suddenly  given  up  her  evolu- 
tion for  his  sake ;  that  she  had  not  suddenly  begun  in 
him  a  new  creation  ;  but  that  here,  as  elsewhere,  she  had 
proceeded  quietly,  gradually,  naturally,  and  that  man 
were  thus  nothing  more  than  the  last  link  of  the  inter- 
minable series  of  animals,  nothing  more  than  a  *  de- 
veloped ape.'  The  first  thought  that  would  then 
obtrude  itself  upon  us,  would  be  that  the  facts  were  not 
altered  in  the  slightest  degree  ;  that  man  would  remain 
as  he  is,  with  the  same  shape,  the  same  face,  the  same 
gait,  the  same  gestures,  the  same  dispositions,  powers, 
feelings,  thoughts,  and  with  the  same  dominion  over  the 
apes  as  heretofore.  This  is  very  simple,  very  self-evi- 
dent, but  also  very  important.  For  it  confers  on  him — 
on  man — the  powerful  sensation  that,  as  he  now  is,  he  is 
a  being   of  a  quite  peculiar  kind,  very  different   from 


SUPERFICIAL  OBJECTIONS.  285 

even  the  most  kindred  creature  ;  and,  moreover,  that 
this  pecuHar  nature  is  his  most  pecuhar  property,  whether 
he  received  it  as  a  ready-made  gift,  or  worked  it  out 
laboriously  from  a  lower  condition  in  tens  of  thousands 
of  years.  But  if  his  present  constitution  is  not  in  the 
slightest  degree  injured  by  his  (assumed)  animal  origin, 
neither  can  his  aims  and  tasks,  his  endeavours  and  voca- 
tions— in  short,  his  whole  future — be  any  other  than,  from 
his  entire  nature,  he  must  imagine  and  believe  it  to  be. 
Or  must  the  cultivated  portion  of  mankind  be  really  so 
profoundly  dismayed  by  the  idea  of  descending  from 
apes,  that  in  despair  at  the  impossibility  of  maintaining 
and  improving  the  civilization,  which  by  no  means  fell 
into  their  lap  like  ripe  fruit,  but  which  was  painfully 
acquired,  they  would  abandon  their  business  and  pur- 
suits, their  forms  of  law  and  government,  their  arts  and 
sciences,  and  sink  to  the  level  of  the  Australian  bush- 
men — that  they  would  let  go  that  by  which  they  had 
raised  themselves  so  far  above  the  apes,  and  by  which 
they  are  constantly  raising  themselves  still  higher,  merely, 
because  it  was  once  difficult  to  raise  themselves  above 
these  apes  even  by  a  hair's  breadth  ?  But  what  man 
destined  by  nature  for  a  ruler,  would  have  refused  to 
grasp  the  crown  because  his  father  was  a  hind  ?  Or 
what  born  Raphael  would  have  forsworn  palette  and 
pencil,  because  his  parent  had  been  a  sign-painter  ? 
Mankind,  like  each  individual,  will  use  and  improve  its 
powers  because  it  has  them,  not  because  it  has  obtained 
them  from  hither  or  thither." 

We  give  these  transient  fireworks  their  due,  but  we 
require  more  profound  arguments  whence  to  derive  the 
final  verdict.     To  the  votaries  of  the  doctrine  of  Descent, 


iS6  THE   DOCTRINE   OF   DESCENT. 

its  application  to  man  is  a  simple  deduction  from  a 
general  law,  gained  by  the  method  of  induction.  As 
Goethe  postulated  the  inter-maxillary  bone  in  man 
even  before  he  had  seen  or  proved  it,  so  must  the  doc- 
trine of  Descent  extend  to  man  all  its  results  and  more 
or  less  plainly  demonstrated  laws.  The  deduction  is 
effected  by  the  accumulated  observations  of  compara- 
tive anatomy,  evolutionary  history,  and  palaeontology, 
checking  and  confirming  one  another.  Thus,  for  all 
who  are  not  satisfied  with  belief  in  miracle  and  sub- 
jection to  the  hypothesis  of  a  revelation,  nothing  remains 
but  the  doctrine  of  Descent.  To  apply  it  to  man  is  not 
more  hazardous,  but,  on  the  contrary,  as  inherently  neces- 
sary, as  it  is  for  us  zoologists  to  make  use  of  it  in  judg- 
ing some  polype  hitherto  unknown,  a  star-fish  or  a  mouse. 
This  our  adversaries  deny.  Man,  they  say,  has  qualities 
which  separate  him  absolutely  from  the  animal,  and, 
assuming  the  doctrine  of  Descent  generally,  preclude  its 
applicability  in  this  one  case.  To  this  assertion,  so  fre- 
quently to  be  heard,  we  will,  in  the  first  instance,  oppose 
a  general  remark  as  to  the  apprehension  of  human 
nature. 

It  is  commonly  overlooked  that,  quite  regardless  of 
the  validity  of  the  doctrine  of  Descent  or  even  of  its 
existence,  there  is  a  notable  inconsistency  In  the  Idea  of 
humanity.  The  philosophy  of  history  has  regarded 
mutability,  which  is,  in  fact,  capability  of  progress,  as 
the  essence  of  human  nature.  But  if  any  sort  of  in- 
separable dependence  of  the  mind  upon  the  body  be 
admitted,  as  is  the  case  with  all  but  an  extreme 
spiritualistic  party,  the  progress  of  mental  power  in 
mankind  was  inconceivable  without  some  parallel  trans- 


THE  BODY  OF   MAN.  287 

formation  of  the  bodily  substratum  extending  beyond 
the  limits  of  mere  variability.  Even  on  the  assump- 
tion that  the  mind  forms  its  own  organ,  the  brain,^ 
the  specific  idea  of  man  would  necessarily  have  con- 
sisted in  bodily  improvement,  as  contrasted  with  the 
supposed  rigidity  of  the  animal  organism.  For,  in 
principle,  it  is  the  same  whether  changes  take  place 
perceptibly  in  arms  and  legs,  or  imperceptibly  to  the 
eye,  in  the  molecules  of  the  brain.  We  are,  therefore, 
only  retrieving  the  shortcomings  of  philosophy  when 
we  attribute  to  the  bodily  mutability  of  man  the  exten- 
sion which  accrues  to  it  from  the  applicability  of  the 
doctrine  of  Descent  to  the  particular  case. 

The  bodily  accordance  betwixt  man  and  animal  leaves 
the  doctrine  of  Descent  so  little  to  desire,  that  the  ap- 
prehension of  Mephistopheles  lest  grovelling  humanity 
should  finally  be  alarmed  at  his  likeness  to  the  Deity, 
might  far  rather  be  applied  to  his  likeness  to  the  animal. 
The  human  body,  like  the  body  of  every  animal,  points 
in  its  evolution  to  an  elaboration  from  the  undifferen- 
tiated to  the  specialized  form.  The  general  distribution 
of  the  body  and  the  development  of  the  several  organs 
is  common  to  man  and  all  mammals,  and  in  the  earlier 
stages  of  the  embryonic  state  to  all  vertebrate  animals, 
and  indicates  this  general  kinship.  The  existence  there- 
fore of  a  discoidal  placenta  (unless  we  prefer  a  special 
reiterated  new  creation  of  this  organ  of  development,  in 
which  the  Creator  adhered  to  the  pattern  of  the  placenta 
of  the  lemurs,  rodents,  insectivora,  bats,  and  apes)  reduces 
U3  to  the  alternative  that  in  the  natural  and  to  us  unknown 
development  of  man,  chance,  or  some  quite  different 
chain  of  causes,  led  in  this  case,  as  in  the  other,  to  the 


288  THE   DOCTRINE   OF   DESCENT. 

discoidal  placenta,  or  that  the  accordance  is  based  on 
consanguinity  with  the  discoido-placental  mammals.  We 
have  already  (p.  272)  objected  to  the  inference  that  all 
mammalian  orders  are  akin,  should  be  drawn  with  cer- 
tainty from  the  superficial  accordance  of  the  placenta, 
and  we  must  therefore  justify  ourselves  now,  when  we 
lay  a  stress  on  the  accordance  of  the  placenta  of  man 
and  apes.  The  orders  mentipned  above  all  possess  a 
placenta  of  small  extent  and  discoidal  form.  In  the 
shape  of  this  disc,  and  in  the  number  and  distribution 
of  the  blood-vessels  in  the  umbilical  cord  by  which  the 
foetal  respiration  and  nutrition  are  carried  on,  sundry 
varieties  occur.  Thus  in  the  family  of  the  Pithecoid 
apes,  the  placenta  falls  into  two  discs,  whereas  the 
umbiHcal  cord  agrees  with  that  of  man  ;  in  the  American 
apes,  on  the  contrary,  the  placenta  is  simple  and  the 
blood-vessels  are  different.  In  the  orang  and  gorilla  we 
know  nothing  of  these  organs,  but  the  chimpanzee  agrees 
with  man,  in  that  it  has  a  simple  discoidal  placenta 
with  two  conducting  (arterise  umbilicales)  and  one  re- 
conducting vessel  (vena  umbilicalis). 

With  a  general  similarity  of  the  human  placenta  with 
that  of  the  discoido-placental  mammals,  man  is  specifi- 
cally nearer  to  one  at  least  of  the  so-called  Anthropoid 
apes,  than  this  one  is  to  the  other  apes.  And  thus  the 
constitution  of  the  placenta  is  certainly  of  great  impor- 
tance in  discriminating  the  systematic  position  of  man. 
Enormously  improbable  as  is  the  chance  contemplated 
above,  equally  probable  and  solely  credible  is  con- 
'^^anguinity  ;  and  with  regard  to  general  organization,  in 
any  specific  comparison  of  man  with  the  mammalia,  the 
apes  must  occupy  the  foreground. 


MAN  AND  APES.  289 

This  comparison  has  been  admirably  conducted  by 
Huxley  and  Broca.*'^  The  latter  has  set  himself  the  task 
of  investigating,  solely  as  a  descriptive  anatomist  and 
zoologist,  regardless  of  all  dispute  as  to  principle,  and 
undisturbed  by  the  doctrine  of  Descent,  whether  the 
anatomical  constitution  of  man,  as  compared  with  that 
of  the  ape,  justifies,  on  general  zoological  principles,  the 
union  of  the  two  in  a  single  order — Primates.  Huxley 
proves  that  the  anthropomorphous  apes  (gibbon,  chim- 
panzee, orang,  gorilla)  differ  from  the  lower  apes  much 
more  than  from  man  ;  and  that  if  we  are  obliged  to 
assume  the  reciprocal  consanguinity  of  the  apes,  the 
common  derivation  of  the  anthropomorphous  apes  and 
man  is  at  least  equally  natural. 

Between  the  peripheral  members  of  the  systematic 
groups  of  monkeys — for  instance,  between  the  American 
Sahuis  and  the  Old-World  Pavians  and  Anthropomorpha 
— notable  differences  exist  in  the  constitution  of  the  limbs 
and  other  parts  of  the  skeleton,  together  with  the  soft 
parts  belonging  to  them,  in  the  muscles  especially,  as 
well  as  in  dentition  and  the  structure  of  the  brain.  It 
is  false  to  call  apes  quadrumana,  for  within  the  order 
of  the  apes  the  contrast  between  hand  and  foot  makes 
its  appearance  in  its  essential  anatomical  attributes, 
and  in  the  anthropomorphous  apes,  in  the  gorilla  espe- 
cially, it  is  almost  as  distinct  as  in  man. 

Luca,  the  anatomist  renowned  for  his  careful  measure- 
ments of  the  cranium,  imagines  that  he  has  discerned 
a  highly  important  demarcation  between  man  and  the 
.ipe.  In  the  ape,  the  three  bones  forming  the  axis 
of  the  skull,  the  basi-occipital  bone,  and  the  two  sphe- 
noid bones,  lie  almost  in  a  line,  whereas  in  man  there 


290  THE   DOCTRINE   OF   DESCENT. 

is  a  double  flexure  of  this  axis  ;  moreover,  in  the  apes 
the  angles  increase  with  age,  which  in  man  decrease,  and 
vice  versa.  Likewise  in  man  the  occipital  foramen 
becomes  more  horizontal  with  age,  more  vertical  in  the  ape. 
But  all  this  shows  only,  what  the  doctrine  of  Descent 
asserts,  that  the  two  series,  ape  and  man,  diverge  from 
one  another,  and  that  the  youthful  individuals  are  more 
alike  than  the  older  ones, — that  the  ape  as  he  grows  be- 
comes more  bestial ;  man,  as  the  riddle  of  the  sphinx 
already  intimated,  more  human.  The  flexure  of  the 
basal  bone  and  the  horizontal  position  of  the  occipital 
foramen  occasions  the  upright  gait,  wherewith  the 
diflerentiation  between  hands  and  feet  is  completed. 
This  flexure  of  the  cranial  axis  may  therefore  still  be 
emphasized  as  a  human  character,  in  contradistinction 
to  the  apes ;  the  peculiar  characteristic  of  an  order  can 
scarcely  be  elicited  from  it ;  and  especially  as  to  the 
question  of  Descent,  this  circumstance  seems  in  no  way 
decisive. 

Not  only  as  regards  hand  and  foot,  but  also  in  denti- 
tion and  brain,  the  anthropomorphous  apes  approach 
man  much  more  nearly  than  they  do  the  inferior  wide- 
nosed  monkeys  of  the  New  World.  These,  have  six 
molar  teeth,  and  their  brain  displays  the  imperfec- 
tions of  the  brain  of  the  lemurs  and  rodents.  Like 
the  monkeys  of  the  Old  World,  on  the  contrary,  the 
anthropomorphous  apes  possess  five  molar  teeth,  and 
every  portion  of  the  human  brain,  even  to  the  hippo- 
campus minor,  is  likewise  present.  The  dispute  as 
to  this  insignificant  portion  of  the  brain,  which 
R.  Owen  claimed  as  an  exclusively  human  charac- 
teristic,   possesses    a    merely    historic    intere-^t,    since, 


MAN   AND   APES.  29 1 

in  conjunction  with  the  posterior  corner  of  the  lateral 
ventricle,  it  has  been  exhibited  by  a  number  of  distin- 
guished anatomists  in  the  orang  and  chimpanzee. 

Thus,  for  those  who  will  not  relinquish  their  hope  of 
finding  specific  distinctions  between  the  brain  of  man 
and  ape,  there  remain  only  the  furrows  and  ridges  on  the 
surface  of  the  cerebrum,  the  so-called  convolutions  of  the 
brain.  But  here,  again,  it  is  in  vain  to  look  for  funda- 
mental differences,  unless  the  chief  stress  is  to  be  laid 
upon  the  circumstance  that  in  the  human  embryo  the 
folds  commence  in  the  frontal,  in  the  apes  in  the  supra- 
orbital lobes.  The  constant  convolutions  common  to 
all  human  brains  are  seen  in  the  orang  and  chimpanzee. 
These  convolutions  are  lost,  or  rather  exist  in  less  per- 
fection, in  the  apes  approaching  the  Anthropomorpha  ; 
they  are  totally  absent  in  the  Ouistitis.  But  so  great 
is  the  resemblance  of  the  brain  of  the  two  apes  mentioned, 
with  that  of  man,  that,  as  Broca  says,  **  it  requires  the 
eye  of  an  experienced  anatomist  to  discriminate,  in 
drawings  reduced  to  the  same  dimensions,  their  brain 
from  the  human  brain,  especially  if  the  object  of  compa- 
rison selected,  be  the  brain  of  negroes  or  Hottentots, 
which  are  more  simple  than  those  of  white  men."  A 
desperate  attempt  to  rescue  a  specifically  human  cere- 
bral character  was  made  by  the  lamented  Gratiolet, 
the  anatomist,  of  Paris.  Man  was  to  be  distinguished 
by  the  so-called  transitional  or  bridging  convolutions. 
These  transitional  folds  are  convolutions,  by  which 
the  posterior  lobes  of  the  cerebrum  are  joined  to  the 
anterior  and  lateral  portions.  But  Broca  has  lucidly 
demonstrated  that  it  is  the  same  with  this  as  with 
other  characteristics,  and  that  the  transitional  folds  in 


292  THE   DOCTRINE  OF   DESCENT. 

the  orang,  for  instance,  are  far  more  like  those  of  man 
than  of  the  chimpanzee,  and  that  the  differences  which 
exist  can  at  the  most  have  the  value  of  specific  or 
generic  characters. 

The  distance  between  the  lower  and  higher  apes  is 
far  greater  than  between  the  latter  and  man  ;  and  if  the 
consanguinity  of  the  entire  apedom  is  decisive  in  favour 
of  Darwinistic  views,  there  can  be  the  less  doubt  of  the 
kindred  connection  of  the  Old-World  apes  to  mankind. 
But  the  form  of  the  mature  skull  and  of  the  dentition 
(to  lay  a  stress  upon  these  organs),  preclude  the  idea 
that  the  direct  ancestors  of  man  are  to  be  found  among 
the  apes  now  living.  The  cheap  jest,  produced  with  so 
much  glee,  of  inquiring  why  we  do  not  behold  the  in- 
teresting spectacle  of  the  transformation  of  a  chimpanzee 
into  a  man,  or  conversely,  of  a  man  by  retrogression  into 
an  orang,  merely  testifies  the  crudest  ignorance  of 
the  doctrine  of  Descent.  Not  one  of  these  apes  can 
revert  to  the  state  of  his  primordial  ancestors,  because, 
except  by  retrogression — by  which  a  primordial  condi- 
tion is  by  no  means  attained — he  cannot  divest  himself 
of  his  acquired  characters  fixed  by  heredity  ;  nor  can 
he  exceed  himself  and  become  man ;  for  man  does 
not  stand  in  the  direct  line  of  development  from  the 
ape.  The  development  of  the  anthropoid  apes  has 
taken  a  lateral  course  from  the  nearest  human  progeni- 
tors, and  man  can  as  little  be  transformed  into  a  gorilla 
as  a  squirrel  can  be  changed  into  a  rat.  Man's  kinship 
wnth  the  apes  is,  therefore,  not  impugned  by  the  bestial 
strength  of  the  teeth  of  a  male  orang  or  gorilla,  or  by  the 
crests  and  protuberances  on  the  skulls  of  these  animals. 
A  renowned  zoologist,  one  of  the  few  who  aiihere  to  the 


MAN  AND  APES.  293 

old  belief,  has  taken  the  useless  trouble  of  proving  that 
the  skull  of  the  orang  could  not  possibly  be  transformed 
into  the  human  head.  As  if  the  doctrine  of  Descent  had 
ever  asserted  such  nonsense  !  The  bony  skull  of  these 
apes  has  reached  an  extreme,  comparable  to  that  of  our 
domestic  cattle.  But  this  extreme  appears  only  gra- 
dually in  the  course  of  growth,  and  the  calf  knows  little 
of  it,  but  possesses,  as  we  have  already  mentioned,  the 
cranial  form  of  its  antelope-like  ancestors.  In  the  pre- 
sent antelopes,  and  likewise  in  goats  and  sheep,  this 
form,  transitory  in  the  calf,  has  remained  stable.  Now, 
as  the  youthful  skull  of  the  anthropomorphous  apes  exhi- 
bits, with  undeniable  distinctness,  a  descent  from  proge- 
nitors with  a  well-formed  and  still  plastic  cranium,  and  a 
dentition  approximating  to  that  of  man,  the  transforma- 
tion of  these  parts  in  conjunction  with  the  brain,  the 
latter  by  reason  of  its  persistently  small  volume,  has,  as 
it  were,  struck  out  a  disastrous  path,  while  in  the  human 
branch,  selection  has  effected  a  higher  conservation  of 
these  cranial  characters. 

With  this  falls  also  the  objection  recently  raised  by  the 
venerable  Karl  Ernest  v.  Baer,  that  it  is  inconceivable 
how,  from  the  monkey's  feet,  arranged  for  climbing  and 
grasping,  the  human  foot,  adapted  for  flat  treading  and 
walking,  should  be  evolved  in  the  struggle  for  existence. 
The  tendency  to  oppose  the  big  toe  to  the  others,  that  is, 
to  a  prehensile  foot,  is  known  to  be  a  human  attribute,  and 
this  tendency  is  certainly  inherited.  How  far  the  capa- 
city for  climbing  may  have  been  developed  in  the  pri- 
mordial ancestors,  is  as  much  unknown  as  these  primordial 
ancestors  themselves.  Thus  the  aptitude  in  climbing 
shown  by  most  of  the  present  monkeys  is  only  remotely 


294  THE   DOCTRINE   OF   DESCENT. 

connected  with  the  inaptitude  of  man,  and  as  a  criterion 
of  consanguinity,  can  hardly  be  taken  into  consideration. 

While  requiring  by  logical  deduction,  a  common  origin 
for  man  and  the  anthropomorphous  apes,  the  doctrine  of 
Descent,  as  it  is  almost  superfluous  to  say,  repudiates  the 
senseless  demand  for  intermediate  forms  between  man 
and  the  gorilla.  What  future  times  may  perhaps  dis- 
cover, are  intermediate  forms  which  go  back  to  the  com- 
mon point  of  derivation  of  the  present  apes  and  of  man. 
And  thus,  notwithstanding  the  very  close  relations  already 
discussed,  there  remains  the  chasm  which  is  approxi- 
mately expressed  by  the  comparative  weights  of  the 
lowest  human  brain  yet  measured  and  the  brain  of  the 
gorilla.  The  brain  of  a  bushwoman,  normally  efficient 
after  the  manner  of  her  tribe,  amounted  to  2  lbs.  4  ozs. 
(Cuvier's  brain  weighed  4  lbs.  4  ozs.),  that  of  a  gorilla 
may  be  estimated,  from  the  capacity  of  the  cranium, 
at  about  i  lb.  6  ozs.,  which  gives  the  approximate 
ratio  of  3  :  2.  But  exalted  above  the  animal  as  man 
may  feel  himself  in  his  bodily  nature,  in  this  again  he 
forms  no  exception,  as  many  animal  forms  occupy  an 
equally  isolated  position  with  reference  to  their  unmis- 
takably nearest  kindred. 

Need  we  imagine  a  twofold  creation  of  vertebrate 
animals,  because  the  lancelet  is  now  separated  from  the 
fishes  by  a  whole  scale  of  intermediate  forms  no  longer 
extant }  The  example  of  the  horse  is,  among  others, 
highly  instructive  in  this  case.  Let  us  bear  in  mind  that, 
in  the  nature  of  the  limbs  and  teeth,  this  genus  differs 
far  more  from  all  other  extant  graminivora  than  man 
differs  from  the  ape.  Had  not  the  fossil  ungulates  been 
found  which  demonstrate  ihe  common  origin  of  thehor.se 


DfeFTCIENCY  OF  INTERMEDIATE  FORMS.  295 

with  the  didactyles  and  multidactyles,  we  should  still  not 
deem  th(i  horse  a  special  miraculous  creation,  but  incon- 
trovertibly  deduce  his  true  kinship  with  the  other  ungu- 
lata.  This  pure  deduction  is  not  requisite,  as  the  proge- 
nitors of  the  liorse  are  present  in  conspicuous  remains ; 
and,  as  we  have  already  seen,  elicited  in  R.  Owen,  half 
a  century  ago,  the  conviction  of  a  direct  metamorphosis 
of  the  tridactyle  genera  into  the  unidactyle.  Our  acquaint- 
ance with  the  tridactyle  horses  was  a  lucky  chance  ;  they 
were  indigenous  in  those  parts  of  Europe  which  have 
been  most  diligently  laid  bare  and  explored  in  behalf  of 
Palaeontology. 

But  that  our  museums  are  still  destitute  of  the  fossil 
progenitors  of  man,  is  not  more  strange  than  the  defi- 
ciency, hitherto  existing,  of  intermediate  forms,  which, 
for  example,  would  conclusively  decide  the  position  of 
the  Dinotherium  in  the  system.  We  will  also  refer  again 
to  the  elephants,  who,  with  their  nearest  ally,  the 
mastodon,  occupy  towards  the  other  Pachydermata  a 
position  elucidated  by  no  fossils,  and  far  more  isolated 
than  that  of  man  to  the  apes.  We  hope  herewith  to 
have  shown  that  the  argument  that,  by  peculiarities  not 
bridged  over, — by  upright  gait,  comparative  hairlessness, 
chin,  preponderance  of  brain,  &c., — man  betrays  a  posi- 
tion absolutely  apart,  cannot  be  admitted  by  comparative 
anatomy  and  pal^eontolog>^  The  demand,  therefore,  that 
the  adherents  of  the  doctrine  of  Descent  should  produce 
the  intermediate  forms  which  at  one  time  necessarily 
existed,  can  be  made  only  by  dilettantes  to  whom  the 
province  of  life,  as  a  w^hole,  has  remained  a  sealed  book. 

As  we  observed  before,  the  bodily  nature  of  man  is 
sometimes  ceded  to  natural  inquiry  as  a  means  of  muie 


296  THE  DOCTRINE  OF  DESCENT. 

certainly  rescuing  the  other  side  of  the  dualism.  But 
here,  too,  we  will  not  be  defrauded  of  our  say  and  our 
own  opinion.  The  mental  powers  of  man,  in  their  origin, 
growth,  and  effects,  are  likewise  susceptible  of  investiga- 
tion, and  psychology  only  too  long  thought  it  possible 
to  elude  physiology.  Let  us,  therefore,  proceed  in  good 
heart  to  a  short  examination. 

It  is  universally  admitted  that  a  certain  relationship, 
or  analogy,  exists  in  the  psychical  capacity  of  the  higher 
animals  and  man.  Reason  alone,  it  is  said, — the  essence 
of  psychical  agencies  by  which  man  attains  self-con- 
sciousness, and  rises  to  abstract  conceptions,  combines 
ideas,  especially  religious  ideas,  and  lives  in  art  and 
science, — this  the  animal  does  not  possess.  We  reply 
that  animals  certainly  do  not  possess  this  degree  of 
mental  development,  but  neither  does  man  possess  it 
in  lower  phases  of  evolution. 

The  soul  of  the  new-born  infant  is,  in  its  manifestations, 
in  no  way  different  from  that  of  the  young  animal ; 
these  manifestations  are  the  functions  of  the  infantine 
neivous  system;  with  this  they  grow  and  are  developed 
together  with  speech.  The  grade  to  which  this  de- 
velopment rises  is  generally  dependent  on  the  preceding 
generations.  The  psychical  capacities  of  each  indi- 
vidual bear  the  family  type,  and  are  determined  by 
the  laws  of  heredity.  For  it  is  simply  untrue  that, 
independently  of  colour  and  descent,  each  man,  under 
conditions  otherwise  alike,  may  attain  a  like  pitch  of 
mental  development.  As  a  proof  of  this  primary 
equality  of  mankind,  single  instances  of  gifted 
negroes  and  Indians  are  held  up  to  us.  But  these 
have  behind  them    unnumbered  generations   practised 


MENTAL  TRCGRESS.  297 

in  multifarious  employments,  skilled  in  human  inter- 
course, even  if  it  be  one-sided  ;  and  if  these  rare  pheno- 
mena are  thoroughly  investigated,  they  still  remain 
behind  the  average  individuals  of  advanced  races.  Now 
it  is  certain  that  in  each  race,  each  individual  passes 
through  grades  in  the  scale  of  mental  development, 
which,  in  perfect  analogy  with  the  laws  of  anatomical 
development,  are  universally  valid ;  whereas,  as  we 
have  seen,  the  psychological  peculiarities  of  the  race  be- 
come valid.  But  it  is  in  mankind  as  in  the  individual ; 
in  the  lapse  of  time,  it  has  acquired  those  higher  powers 
of  mind  which  we  call  Reason. 

History  shows,  and  no  one  denies,  a  mental  advance, 
but  only  in  nations  which  have  taken  part  in  histor>', 
and  only  so  long  as  this  part  and  the  exercise  of  the 
mental  organs  has  been  continued.  But  inferior  human 
races  exist — we  may  also  call  them  human  species — 
which  are  related  to  the  others,  as  are  lower  animals  to 
higher.  It  might  even  be  given  as  the  characteristic  of 
the  genus  man,  that  its  species  occupy  such  extraor- 
dinarily different  grades  of  mental  condition.  We  are 
not  misled  by  the  contrary  statements  of  missionaries 
and  other  philanthropists  ;  by  the  talk  of  human  dignity 
and  divine  resemblance  ;  nor  do  we  seek  for  consolation 
in  the  development  still  to  be  expected  in  all  nations 
which  have  hitherto  lagged  behind.  It  is  indeed  self- 
evident  from  the  theory  of  descent  and  selection,  that 
many  of  the  races  now  standing  far  behind  in  a  mental 
point  of  view  will  in  future  have  made  a  great  advance. 
I'ut  for  others,  if  we  contemplate  the  ethnology  and 
anthropology  of  savages,  not  from  the  standpoint  of 
philanthropists  and  missionaries,  but  as  cool  and  sober 


298  THE   DOCTRINE   OF   DESCENT. 

naturalists,  destruction  in  the  struggle  for  existence  as 
a  consequence  of  their  retardation  (itself  regulated  by 
the  universal  conditions  of  development),  is  the  natural 
course  of  things. 

If  we  examine  the  mental  condition  of  mankind,  and 
compare  it  with  the  psychical  capacities  of  animals,  we 
must  not  take  the  average  Indian  or  European  as  our 
standard,  but  the  Australian  and  Papuan  races,  which 
in  body  also  have  remained  at  a  grade  which  the  other 
more  favoured  races  outgrew  in  pre-historic  times  long 
past.  Many,  it  is  true,  overcome  all  difficulties,  inas- 
much as,  assured  of  an  equalizing  human  dignity  as  of 
a  dogma  needing  no  further  foundation,  they  are  ready 
with  the  assertion  that  it  is  impossible  to  doubt  that 
they  have  retrograded  from  a  higher  mental  develop- 
ment and  sunk  into  barbarism.  But  if  this  possibility 
might  be  admitted  as  regards  some  few  races,  such  as 
the  Fuegians;  in  others,  in  the  Australians  for  instance, 
any  real  evidence  of  this  previous  more  elevated  condi- 
tion is  wanting. 

The  superior  mental  prerogatives  which  are  supposed 
to  separate  man  from  the  animal,  hinge  more  or  less  on 
the  following  points. 

Man  alone,  it  is  said,  is  capable  of  development  or 
progress.  Specifically,  human  is  all  progress  regulated 
and  effected  by  human  speech,  for  many  animals  like- 
wise possess  the  gift  of  communication.  But  if  we  are 
not  to  imagine  man  as  having  advanced  from  all  eternity, 
the  question  is,  how  was  this  advance  initiated,  and  the 
whole  concern  is  fundamentally  reduced  to  the  problem 
of  the  origin  of  language.  We  will  return  to  this  subject. 
Progress  in  general  is  not  however  to  be  denied  to  the 


FREE  WILL.  299 

animal.  Who  can  question  that  some  canine  races,  of 
which  the  descent  from  stupid  jackals  and  wolves  is  as 
good  as  certain,  have  raised  themselves  mentally  far  above 
their  ancestry  ?  Who,  that  has  read  the  comprehensive 
investigations  of  H.  Miiller,  the  brother  of  our  Fritz 
Miiller,  can  doubt  that  the  honey-bee,  as  it  gradually 
attained  its  bodily  advantages  and  peculiarities,  de- 
veloped likewise  the  higher  mental  powers,  correspond- 
ing with  the  more  minute  and  complex  organism  of  her 
brain  ?  Man — such  is  the  thesis  we  propound,  reserving 
the  question  of  language — differs  from  many  animals 
only  in  the  degree  and  means  of  progress.  It  is  there- 
fore unscientific  to  contrast  humanity  and  animality  in 
the  abstract. 

Man  alone,  it  is  further  maintained,  has  a  free  will. 
In  so  far  as  the  more  highly  developed  man  acts  in 
accordance  with  philosophical,  moral  and  religious 
principles,  for  which  he  is  indebted  to  education  and 
instruction — in  so  far  as  he  is  able  to  apprehend  ideals, 
and  strive  after  them  with  his  own  mental  and  bodily 
power,  this  command  of  will  may  be  readily  admitted, 
although  we  know  that  this  "  freedom  "  is  likewise  the 
collective  result  of  natural  causes.  But  the  more  simple 
and  uniform  the  conditions  of  life,  the  more  do  the 
dealings  of  men  lose  the  semblance  and  character  of 
freedom,  and  the  more  does  the  individual  act  after  the 
will  of  the  tribe — I  might  say,  of  the  herd — that  is  to  say, 
instinctively.  In  this  case  actions  are  not  performed 
even  with  the  astounding  premeditation  with  which 
some  few  happily  organized  individual  animals  of  some 
few  species  turn  the  circumstances  to  account  with 
apparently   complete  free   will.     The  free  will  of   the 


300  THE  DOCTRINE  OF  DESCENT. 

morally  elevated  man,  is  no  common  property  of  all 
mankind. 

Man  alone,  and  all  men,  are  supposed  to  have  a  con- 
science. We  consider,  on  the  contrary,  that  conscience, 
which  is  known  to  be  utterly  lost  in  many  individuals 
of  even  the  most  civilized  nations,  is,  like  moral  will, 
a  result  of  education  in  some  few  races  and  tribes.  Fear 
of  detection  after  a  bad  action,  is  not  conscience ;  and 
that  well-trained  dogs  have  sensations  of  conscientious 
shame  far  superior  to  the  animal  terror  of  savage 
cannibals  after  they  have  wrought  the  murder  of  their 
fellow-men,  it  is  impossible  to  deny.  Of  this,  evidence 
in  profusion  is  accumulated  in  the  anthropological  com- 
pilations of  Waitz. 

That  a  consciousness  of  the  Divine  existence  is  a 
fundamental  property  of  all  men,  we  likewise  hold  in 
question.  It  is,  again,  an  established  phrase  that  the  most 
barbarous  nations  are  guided  by  emotions  and  cravings, 
however  obscure,  towards  the  unknown  God.  This 
assumption  is  as  old  as  the  well-known  attempt  to  prove 
the  existence  of  God,  "  De  quo  omniinn  natura  consentit, 
id  veritm  esse  necesse  est "  (That  in  which  all  intuitively 
agree,  must  necessarily  be  true).  How  often  has  this 
saying  of  Cicero  been  thoughtlessly  repeated }  This  idea 
of  God  is,  however,  as  little  intuitive  as  the  discrimination 
of  good  and  evil  by  the  conscience.  Others  maintain 
the  contrary.  Thus  Gcrland  says  of  the  Australians  :  ^^ 
•'  The  statement  that  Australian  civilization  indicates  a 
higher  grade  is  nowhere  more  clearly  proved  than  here 
(in  the  province  of  religion),  where  everything  resounds 
like  the  expiring  voices  of  a  previous  and  richer  age ; 
but  we  in  no  way  receive  the  impression  that  \vc  are 


AUSTRALIAN   IDEA  OF  GOD.  3OI 

dealing  with  stagnation  or  incomplete  development. 
Thus  the  idea  that  the  Australians  have  no  trace  of 
religion  or  mythology  is  thoroughly  false.  But  this 
religion  is  certainly  quite  deteriorated,  and  haii  degene- 
rated into  a  wild,  disjointed,  and  often  incredibly  absurd 
demonology,  into  a  superstitious  fear  of  apparitions." 

But  when  a  few  lines  later  in  the  work  quoted,  we  are 
informed  that  the  natives  to  the  west  of  the  Liverpool 
range,  ascribe  everything  in  nature  which  they  cannot 
explain  to  the  Devil-Devil,  and  that  this  is  manifestly 
only  a  name,  derived  from  the  English  Devil,  for  a  Deity 
of  whom  they  have  not  preserved  any  distinct  conception, 
the  shallowness  of  this  evidence  in  favour  of  the  hypo- 
thesis of  a  previous  standpoint,  now  sunk  into  oblivion, 
enables  us  to  infer  the  value  of  the  other  instances.  We 
have  far  more  reason  to  believe  this  low  state  of  mental 
development  in  harmony  with  the  bodily  condition, 
when  we  hear  that  the  natives  of  the  Gulf  of  St.  Vincent 
and  the  neighbourhood  of  Adelaide  are  extremely  hairy, 
and  that  even  the  brown-  coloured  down  of  the  children 
is  so  abundant  and  so  long,  that  the  skin  of  boys  of 
five  or  six  years  of  age  assumes  a  furry  appearance. 
But,  contrary  to  all  experience  and  history,  w^e  are 
required  to  believe  **  that  the  inhabitants  of  the  northern 
parts  of  Australia  are  the  most  aboriginal,  for  "they 
are  the  most  civilized,  as  well  as  the  best  developed,  in 
mind  and  body ;  they  only  are  fixed  in  one  dwelling 
place ;  and  in  any  case  the  supposition  is  easier  and 
more  natural  that  the  other  natives  should  have  de- 
generated, with  their  eternal  wanderings,  than  that  the 
former,  fixed  by  the  more  convenient  territory,  should 
have  raised  themselves." 


302  THE   DOCTRINE   OF   DESCENT. 

This  Inverts  all  that  has  hiUierto  been  called  anthro- 
pology. Moreover,  there  are  even  very  advanced  nations 
without  any  consciousness  of  God.  Schvveinfurth  relates 
that  the  Niam-Niam,  that  highly  interesting  dwarf  people 
of  Central  Africa,  have  no  word  for  God,  and  therefore 
it  must  be  supposed,  not  the  idea  ;  and  Moritz  Wagner 
has  given  a  whole  selection  of  reports  on  the  absence 
of  religious  consciousness  in  inferior  nations.  When,  in 
spite  of  all  these  corroborations,  it  is  always  retorted 
afresh  that  even  among  the  lov/est  savages  som.e  sort  of 
feeling  of  superior  powers  is  manifested,  the  dispute 
finally  results  in  mere  verbal  criticism,  which  has  no 
farther  interest  for  the  doctrine  of  Descent. 

And  yet  we  cannot  leave  this  subject  without  alluding 
to  a  fact,  universally  known,  but,  strange  to  say,  not  as 
yet  employed  in  this  connection,  and  which,  as  it  would 
seem,  is  by  itself  sufficient  to  invalidate  the  assertion 
that  the  idea  of  God  is  immanent  in  human  nature.  We 
mean  the  fact  that  many  millions  in  the  most  cultivated 
nations,  and  among  them  the  most  eminent  and  lucid 
thinkers,  have  not  the  consciousness  of  a  personal  God  ; 
those  millions  of  whom  the  heroic  David  Strauss  became 
the  spokesman  when  he  adopted  for  his  own  the  motto 
of  his  favourite,  Ulrich  von  Hutten  :  I  have  dared  it — 
Jacta  est  alea  1 

And  now  as  to  Language.?  All  modern  philologists 
agree  that  languages  are  developed,  and  that  most  pro- 
bably all  linguistic  families  pass  through  three  stages.  In 
the  stage  of  the  radical  languages  all  words  are  roots, 
and  are  merely  placed  side  by  side.  In  the  second  stage, 
that  of  the  agglutinated  languages,  one  root  defines  the 
other,  and  the  defining  root  ultimately  becomes  merely 


DEVELOPMENT  OF  LANGUAGE.  303 

a  determinative  element.  Finally,  in  the  inflected 
languages,  the  determinating  element,  of  which  the 
determinating  significance  has  long  vanished  from  the 
national  consciousness,  unites  into  a  whole  with  the 
formative  element.  As  we  have  said,  this  development, 
in  which  retrogression  takes  an  extensive  share,  is  uni- 
versally admitted.  Opinions  differ  only  as  to  the  origin 
of  the  linguistic  material,  which  the  acuteness  of  the 
philosophers  extracts  in  the  guise  of  "  roots."  A  great 
authority.  Max  Miiller,*^  discerns  in  the  existence  of  the 
roots  evidence  of  the  absolute  separation  of  man  from 
the  animal.  While  Locke  says  that  man  is  distinguished 
from  the  animal  by  the  power  of  forming  general  ideas, 
the  philologist  ought  to  say  that  human  language  is 
distinguished  from  the  animal  capacity  of  communica- 
tion by  the  power  of  forming  roots.  To  trace  up  all 
words  to  imitation  and  exclamatory  sounds  is  inadmis- 
sible, as  we  most  frequently  come  upon  roots  of  fixed 
form  and  general  meaning  which  are  inexplicable  in 
themselves.  He  deems  the  existence  of  these  ready- 
made  roots,  before  which  linguistic  science  stands  help- 
less, an  insurmountable  impediment  to  the  apprehension 
of  man  as  a  link  in  the  general  evolution  of  organisms. 
This  point  excepted,  this  excellent  scholar  naturally 
admits  all  those  phenomena  of  heredity,  acquisition, 
and  degeneration,  which  are  manifested  in  the  laws  of 
language,  and  find  their  most  perfect  analogies  in  our 
doctrine  of  Descent.  If,  for  instance,  we  compare  Zend 
with  Sanscrit,  and  hear  several  of  its  words  explained, 
we  are  at  once  reminded  of  the  rudimentary  organs  and 
their  significance.  A  host  of  anomalies  are,  like  the 
isolated    organisms    of    present   times,    primaeval    and 


304  THE  DOCTRINE  OF   DESCENT, 

peculiarly  normal  remnants  and  witnesses  of  b}'gone 
linguistic  periods.  In  short,  down  to  the  minutest 
details,  linguistic  research  stumbles  on  accordance  and 
analogies  with  the  doctrine  of  the  derivation  of 
organisms.  And,  forsooth,  we  are  to  halt  before  the 
origin  of  language  as  before  a  something  incomprehen- 
sible and  inscrutable ! 

This  is  not  done,  however,  by  the  majority  of  com- 
parative linguists  in  the  present  day.  Though  Max 
Miiller  calls  the  roots  "  phonetical  fundamental  types 
produced  by  a  power  inherent  in  human  nature,"  though, 
according  to  him,  man  in  a  more  perfect  state  possessed 
the  power  of  giving  to  the  reasonable  conceptions  of  his 
niind  a  better  and  more  subtle  expression,  the  talented 
Lazarus  Geiger  *^  terms  the  hypothesis  of  a  now  extinct 
power  of  forming  languages,  and  the  other  hypothesis  con- 
nected with  it,  of  a  primordial  state  of  higher  perfection, 
a  recourse  to  the  incomprehensible  and  a  return  to  a 
standpoint  of  mysticism.  For  that  which  is  not  under- 
stood is  not  necessarily  incomprehensible.  It  is  not  our 
business  to  side  with  Geiger,  who  attributes  an  essential 
share  in  the  ejaculation  of  words  to  the  visual  percep- 
tions, or  with  Bleek,  G.  Curtius,  Schleicher,  Steinthal,  and 
many  others,  who  assign  to  the  imitation  of  sounds  the 
first  place  in  the  evocation  of  language.  This  much  is, 
however,  certain,  that  although  those  who  are  not  critical, 
find  Max  Miiller's  standpoint  highly  convenient,  in 
science,  it  is  unique.  In  this  province,  interwoven  as  it 
is  with  the  investigation  of  nature,  the  greater  number 
of  authorities,  on  linguistic  grounds,  comparative  and 
philosophical,  have  been  forced  to  the  conclusion  that, 
from    an   irrational    primordial   state,  man-like   beings 


LANGUAGE  AND   MIND.  305 

gradually  became  human,  while  with  language,  the  work 
ol  many  years,  reason  made  its  appearance. 

As  early  as  185 1,  when  the  doctrine  of  Descent  was 
still  unheard  of,  Steinthal  ^  says  :  "  As  language  arises, 
mind  originates."  Ten  years  after  Darwin,  Geiger 
writes:  "Language  created  reason;  before  language,  man 
was  irrational."  To  him,  and  to  all  who  have  abandoned 
the  standpoint  of  mysticism,  "man  is  a  genus  springing 
from  an  animal  condition  by  means  of  the  origin  and 
unfolding  of  his  idiosyncrasy.  And  this  conclusion  is  not, 
as  orthodoxy  and  reaction  are  anxious  to  impress  upon 
the  multitude,  borrowed  from  Darwinism,  but  deduced 
from  linguistic  inquiry  in  its  own  way,  only  by  a  scientific 
method.  It  need  only  be  indicated  that,  as  Geiger  has 
historically  proved  in  so  many  instances,  "slow  develop- 
ment, the  emergence  of  contrast  from  imperceptible 
deviations,  is  the  cause  that  the  same  word  acquires 
various  meanings  ;"  that  the  creation  of  language  there- 
fore rests  upon  this  process,  and  nowhere  makes  its  ap- 
pearance suddenly  and  abruptly  ;  that  the  so-called  laws 
of  sound  are  habits  of  sound  ;  that  the  special  meaning 
which  a  sound  has  acquired  in  lapse  of  time  is  always  the 
result  of  mere  chance,  or,  in  other  words,  of  development. 

This  deduction  of  Hnguistic  inquiry  most  fully  con- 
firms the  result  of  natural  inquiry.  And  any  one  who 
takes  the  trouble  to  follow  the  course  of  linguistic  science 
will  be  convinced  that  its  champions,  except,  perhaps, 
Bleek,  Schleicher,  and  Friedrich  Miiller,  are  labouring 
rather  to  discredit,  than  to  acknowledge,  the  influence  of 
the  doctrine  of  Descent.  All  the  higher  is  our  estimate 
of  it,  and  therewith  the  most  powerful  objection  to  the  in- 
clusion of  man  in  the  great  law  of  derivation  is  set  aside. 


306  THE  DOCTRINE   OF  DESCENT. 

The  rest  is  incidental  and  a  matter  of  detail.  The 
question  so  often  ventilated,  and  now  thoroughly  worn 
out,  whether  mankind  is  descended  from  one  or  more 
pairs,  is  solved  by  the  inference  that  the  stock  in  which 
language  first  arose,  separated  itself  gradually  from  its 
animal  progenitors,  and  that  the  selection  which  led  to 
language  and  reason  necessarily  took  place  among  large 
communities  of  individuals.  The  scriptural  conception 
of  the  unity  of  the  human  race  would  be  more  nearly 
approached  if  all  linguistic  families  pointed  to  a  single 
source.  But  if  it  could  be  shown  that  certain  linguistic 
families  lead  to  utterly  discordant  roots,  the  investiga- 
tion of  nature  might  furnish  the  inevitable  corollary  that 
language  originated  in  various  parts  of  the  world, — 
in  other  words,  that  a  separation  into  species  took 
place  before  selection  had  reached  the  point  of  forming 
language.  The  latter  case  is  by  far  the  most  probable, 
and  is,  in  fact,  received  as  the  only  one  possible  by  most 
of  the  linguists  occupied  with  this  question,  and  is  most 
especially  defended  by  Friedrich  Miiller.^^  *'At  the 
time,"  he  says,  "  when  there  were  races  and  no  nations, 
man  was  a  speechless  animal,  as  yet,  entirely  destitute 
of  the  mental  development  which  rests  upon  the  agency 
of  language.  Independently  of  the  premisses  unfolded 
by  natural  history,  this  hypothesis  is  forced  upon  us  by 
the  contemplation  of  the  languages  themselves.  The 
various  families  of  languages,  which  linguistic  science 
is  able  to  discriminate,  not  only  presuppose,  by  their 
diversity  of  form  and  material,  several  independent 
origins,  but,  within  one  and  the  same  race,  they  point  to 
several  mutually  independent  points  of  origin." 

In  order  to  afford  the  reader  some  notion  of  the  con- 


RACES  OF   MAN. 


307 


nection  of  the  families  of  nations,  we  give  the  subjoined 
pedigree,  in  which  Friedrich  MuUer  closely  adheres  to 
Haeckel's  sketch. 


It  makes  mention  of  species  and  races  of  mankind, 
the    species    being    regarded    as    no    longer    existing, 


21 


308  THE  DOCTRINE   OF   DESCENT. 

while  the  present  forms  of  man  are  distinguished  only 
as  races.  On  this  subject,  we  shall  not  lavish  many 
words,  since,  examined  in  the  light,  it  is  an  affair  of  words 
only.  In  the  order  of  Primates,  man  constitutes  a  single 
family,  and  represents  it  by  a  single  genus.  Whether 
Negroes,  Caucasians,  Papuans,  American-Indians,  &c., 
.be  called  species  or  races,  matters  little.  The  facility  of 
intercrossing  the  different  nations  would  favour  their 
characterization  as  races  ;  but  as  the  crossing  of  species 
does  not  differ  in  principle  from  the  crossing  of  races, 
and  as  to  the  bodily  varieties  displayed  in  colour, 
hair,  skull,  limbs,  and  other  characters  are  added  the 
profound  differences  of  language,  the  division  of  the 
genus  homo  into  species,  diverging  into  many  races, 
seems  after  all  more  natural.  But  ultimately,  as  in  the 
question  of  species  in  general,  the  individual  feeling  of 
each  person  proves  decisive.  Whether  it  was  a  lucky 
hit  to  found  the  division  of  mankind  on  the  position 
of  the  hairs,  in  tufts  or  equally  distributed  upon  the 
scalp,  and  furthermore  on  the  section  of  the  hair, 
whether  it  he  more  flat  and  oval  or  circular  in  form, 
and  finally  on  the  inclination  to  curl  or  to  lie  stiff  and 
smooth,  the  future  must  decide. 

The  twelve  races  cited  in  the  table  given  above,  may 
be  characterized  by  the  aid  of  natural  history ;  and  as 
within  the  limits  of  the  best  known  races,  languages 
and  families  of  languages  may  be  found,  which  preclude 
any  common  origin,  it  follows  that  the  formation  of 
language  began  only  after  the  still  speechless  primordial 
man  had  diverged  into  races.  In  geological  periods  and 
primordial  history,  all  chronology  is  extremely  decep- 
tive :   we   may,   nevertheless,  acquiesce  in  an  estimate 


ANTIQUITY  OF   MAN.  309 

made  by  iTiedrich  Mliller  as  to  the  development  oi 
the  languages  of  the  Mediterranean  races.  The  Hn- 
guistic  families  of  the  nations  dwelling  chiefly  in  the 
basin  of  the  Mediterranean  are  Basque,  Caucasian, 
Hamito-Semitic  and  Indo-Germanic  languages.  "The 
languages  of  these  four  families,"  says  Friedrich  Miiller, 
"are,  as  is  generally  accepted  by  the  most  competent 
linguists,  not  mutually  related.  If  we  therefore  see 
that  the  Mediterranean  race  includes  four  families  of 
people  in  no  way  related  to  one  another,  the  inference 
is  obvious  that,  as  each  language  must  be  traceable 
to  a  society,  the  single  race  must  have  gradually  fallen 
into  four  societies,  of  which  each  independently  created 
its  own  language.  A  further  inference  is,  that  the 
race,  as  such,  does  not  acquire  a  language ;  for,  were 
this  the  case,  race  and  language  would  now  be  co- 
extensive, which  is  not  the  case. 

"  We  must  therefore  assume  that  at  the  time  when 
the  various  nations  of  the  Mediterranean  race  were  one, — 
the  time  when  man  belonged  to  no  nation,  but  merely 
to  a  race, — mankind  was  destitute  of  language.  Miiller 
considers  3000  years  approximately  sufficient  for  the 
period  elapsing  between  the  divergence  of  the  race  into 
still  speechless  societies,  and  the  epoch  at  which  they 
formed  nations,  separated  and  characterized  by  lan- 
guages ;  a  period  which  might  seem  to  many,  estimated 
as  far  too  short.  If  the  ancient  civilized  people  of  Egypt 
be  now  added  on,  and  the  period  of  its  conjectured 
migration  from  Asia  computed,  "the  year  6,500  before 
the  commencement  of  our  chronology  seems  to  be  the 
earliest  epoch  at  which  we  may  speak  of  a  Hamito- 
Semitic  primaeval  people  in  the  north  of  Europe."    There- 


310  THE  DOCTRINE  OF  DESCENT. 

fore  a  Mediterranean  race  already  existed  12,000  years 
ago.  But  what  space  of  time  was  requisite  to  enable 
primitive  man  to  separate  into  races,  is  entirely  beyond 
computation,  and  the  more  so  as  not  the  slightest  trace 
of  him  has  hitherto  been  found. 

With  the  invariable  testimony  of  Geology  that  the 
periods  of  the  terrestrial  strata  imperceptibly  merged 
into  one  another,  and  that,  especially  from  the  Ter- 
tiary, through  the  Diluvial  period,  to  the  present  age, 
continuity  has  been  only  locally  interrupted,  the  ques- 
tion of  the  "fossil  man,"  formerly  looked  upon  as 
cardinal,  has  assumed  another  aspect.  In  Europe,  man 
lived  with  the  mammoth  and  the  rhinoceros  with  a 
bony  nasal  partition  (Elephas  primogenius,  Rhinocerus 
tichorhinus).  It  has  been  asserted  that  European  man 
existed  as  early  as  the  upper  Tertiary  age,  but  the  evi- 
dence is  disputable.  Such  remains  as  we  have  of  this 
oldest  man  known  to  us,  display  a  high  grade  of  develop- 
ment, and  certainly  belong  to  the  period  at  which  man 
had  already  found  in  language  the  implement  where- 
with gradually  to  free  himself  from  the  dross  of  his 
lowly  origin.  Whether  the  primitive  man  be  found  or 
not,  his  origin  is  certain. 


REFERENCES  AND  QUOTATIONS. 


'  Luthardt,  Apologetische  Vortriige.     7  Vortrag.     P.  129. 

^  Philosophia  quaerit,  theologia  invenit,  religio  possidet  verr 
tatem. 

3  Tageblatt  der  Naturforscher-Versammlung  in  Leipzig,  1872. 
P.  12.     The  discourse  was  also  printed  separately. 

^  A.  Fick,  Physiologie,  i860. 

'  Any  one  who  wishes  to  be  more  deeply  instructed  in  the 
problem  of  sensation,  as  an  universal  primary  characteristic  of  the 
constituent  elements  of  matter,  may  be  referred  to  the  very  lucid 
and  interesting  work,  "  Das  Unbewuste  vom  Standpunkt  der 
Physiologie  und  Descendenztheorie"  (Berhn,  1872).  Published 
anonymously. 

®  L.  Geiger,  Ueber  den  Ursprung  der  Sprache.  (Stuttgart, 
1869.)     P.  207. 

'  Rollet,  Ueber  Elementartheile  und  Gewebe  und  deren  Unter- 
scheidung.     Rollet,  Untersuchungen,  etc.  1871. 

^  Karl  Ernst  v.  Bar,  Ueber  Entwickelungsgeschichte  der 
Thiere,  Beobachtung  und  Reflexion,  1828. 

"  lb.     I.  223. 

'«  lb.     I.  230,  &c. 

"  Credner,  Elemente  der  Geologic,  1872.     P.  253. 

''^  Agassiz,  Essay  on  Classification,  1858.  "  It  exhibits  ever}^- 
where  the  working  of  the  same  creative  Mind,  through  all  times, 
und  upon  the  whole  surface  of  the  globe." 

^^  RUtimeyer,  Beitrage  zur  Kenntniss  der  fossilen  Pferde. 
Verhandlung  der  naturibrschenden  Gesellschaft  in  Basel,  1863. 
111.642. 

^'*  The  passages  are  from  an  occasional  address — Oratio  de 
ellure  habitabili — contained  in  the  Amoenitates  academicae.  "  Initio 


312  THE   DOCTRINE  OF  DESCENT. 

rerum  ex  omni  specie  viventium  unicum  sexus  par  fuisse  creatum, 
suadet  ratio." 

*'  lb.  Non  multum  a  veritate  me  aberratum  confido,  si  dixerim, 
omnem  continentem  terram  fuisse  in  infantia  mundi  aquis  sub- 
mersam  et  »vasto  oceano  obtectam,  praeter  unicam  in  immenso 
hoc  pelago  insulam,  in  qua  commode  habitaverint  animalia  omnia 
et  vegetabilia  laste  germinaverint." 

^^  Tot  numeramus  species,  quot  ab  initio  creavit  infinitum  ens." 

^^  Geoffroy  St.  Hilaire  wrote  to  Cuvier  :  "  Venez  jouer  parmi 
nous  le  role  de  Linne,  d'un  autre  legislateur  de  I'iiistoire  naturelle." 

^^  Ossements  fossiles. 

^' L.  Agassiz,  An  Essay  on  Classification,  1859.     P.  253: — 

"As  representatives  of  Species^  individual  animals  bear  the 
closest  relations  to  one  another  ;  they  exhibit  definite  relations  also 
to  the  surrounding  element,  and  their  existence  is  limited  within  a 
definite  period. 

"As  representatives  of  Ge7iera  these  same  individuals  have  a 
definite  and  specific  ultimate  structure,  identical  with  that  of  the 
representatives  of  other  species,"  etc.     See  also  P.  261  : — 

"  Branches  or  types  are  characterized  by  the  plan  of  their  struc- 
ture ; 

"  Classes^  by  the  manner  in  which  that  plan  is  executed,  as  far 
as  ways  and  means  are  concerned ; 

"  Orders^  by  the  degrees  of  complication  of  that  structure ; 

"  Families^  by  their  form,  as  far  as  determined  by  structure ; 

"  Genera^  by  rhe  details  of  the  execution  in  special  parts ;  and, 

"  Species^  by  the  relations  of  individuals  to  one  another,  and  to 
the  world  in  which  they  live,  as  well  as  by  the  proportions  of  their 
parts,  their  ornamentation,"  etc. 

2°  Haeckel,  Generelle  Morphologic  der  Organismen  (Berlin,  1866). 
II.  323,  &c. 

^'  L'espece  est — "la  reunion  des  individus  descendant  I'un  de 
I'autre  et  des  parents  communs,  et  de  ceux  qui  leur  ressemblent 
autant  qu'ils  se  ressemblent  entr'eux."     Cuvier,  Le  Regne  Animal. 

"^  O.  Schmidt,  Die  Spongien  der  Kiiste  von  Algier,  1868,  and 
Versuch  einer  Spongienfauna  des  atlantischen  Gebietes,  1870. 

'^"^  Haeckel,  Die  Kalkschwamme.  Eine  Monographic  in  Zwei 
Banden,  Text  und  einem  Atlas  mit  60  Tafeln  Abbildungen  (Berlin, 
1872). 


REFERENCES  AND  QUOTATIONS.  313 

**  Hilgendorf,  Ueber  Planorbis  multiformis  in  Steinheimer  Siiss- 
wasserkalk.  Monatsbericht  dcs  Berliner  Akademie  aus  dem  Jahre 
1866.     P.  474,  &c. 

^  Waagen,  Die  Formenreihe  des  Ammonites  subradiatus. 
Beneke's  Beitrage,  1869.     Vol.  2. 

Zittel,  Die  Fauna  der  altem  Cephalopoden  fiihrenden  Tithonbil- 
dvmgen.     Palaontologische  Mittheilungen,  1870. 

Neumayr,  Jurastudien.  Jahrbuch  der  geologischen  Reichsanstalt, 
1871. 

L.  Wiirtenberger,  Neuer  Beitrag  zum  geologischen  Beweise  der 
Darwin'  schen  Theorie,  1873. 

26  Darwin,  The  Variation  of  Plants  and  Animals  under  Domesti- 
cation 1868. 

'^  L.  Oken,  Die  Zeugung,  1805.  Lehrbuch  der  Naturphiloso- 
phie,  1 809-1 1,  PL  3. 

*^  I  have  borrowed  the  following  account  from  my  essay  :  **  Wae 
Goethe  ein  Darwinianer ?"  (Was  Goethe  a  Darwinist?)  Gratz, 
Leuschner  and  Lubinsky,  1871. 

Also  another  small  work  of  mine  :  "  Goethe's  Verhaltniss  zu  den 
organischen  Naturwissenschaften"  (Berhn,  1852).  To  the  pas- 
sages given  in  the  text,  which  might  make  Goethe  appear  as  a 
DarAvinist,  I  may  add  the  following  from  Eckermann's  "  Gesprache 
mit  Goethe"  (3  Ed.  p.  191).  "Thus  man  has  in  his  skull  two 
empty  cavities.  The  question  why  ?  would  not  go  far,  whereas 
the  question  how?  teaches  me  that  these  cavities  are  remains 
of  the  animal  skull,  which  in  those  inferior  organisms  exist  to 
a  greater  degree,  and  are  not  entirely  lost  even  in  man,  notwith- 
standing his  higher  elevation." 

^*  A  somewhat  depreciatiye  opinion  of  Goethe's  importance  in 
this  sphere  is  pronounced  by  V.  Carus  in  his  "  Geschichte  der 
Zoologie"  (Munchen,  1872).  The  reader  may  compare  :  "  How 
Httle,  notwithstanding  his  repeated  study  of  anatomy,  he  had 
gained  a  true  insight  into  the  structure  of  animals,  as  determined 
by  law,  is  testified  by  his  Introduction  to  Comparative  Anatomy. 
He  finds  no  other  means  of  harmonizing  the  dry  details  of  descrip- 
tive anatomy,  and  the  morphology  which  vaguely  hovered  before 
him,  but  by  indicating  the  idea  of  a  primitive  type  for  animals, 
which  he  is,  however,  unable  to  define  or  to  render  in  any  way 
ptilpable  by  more  general    indications.      His  whole  idiosyncrasy 


314  THE   DOCTRINE  OF   DESCENT. 

made  such  a  type  a  necessity  to  him,  not  scientifically,  but  aestheti- 
cally," etc.     P.  590. 

'^^  R.  Owen  has  declared  his  attitude  towards  the  doctrine  of 
descent  in  the  conchiding  chapter  of  his  "Manual  of  the  Com- 
parative Anatomy  of  the  Vertebrata."  It  is  published  sepa- 
rately under  the  title  of  "Derivative  Hypothesis  of  Life  and 
Species,"   1868. 

^^   lb "  such  cause  being  the  servant  of  predetermining 

intelligent  will." 

^2  "  No  one  can  enter  the  saddling-ground  at  Epsom  before  the 
start  for  the  Derby,  without  feeling  that  the  glossy-coated,  proudly- 
stepping  creatures  led  out  before  him  are  the  most  perfect  and 
beautiful  of  quadrupeds.  As  such,  I  believe  the  horse  to  have 
been  predestined  and  prepared  for  man."     lb.  P.  1 1. 

^^  "  I  deem  an  innate  tendency  to  deviate  from  parental  type, 
operating  through  periods  of  adequate  duration,  to  be  the  most 
probable  nature  or  way  of  operation  of  the  secondary  law  whereby 
species  have  been  derived  one  from  the  other."    lb.  P.  22. 

^•*  Lamarck,  Philosophie  Zoologique  (Paris,  1809).  In  the  text 
allusion  is  made  to  the  following  passages  : — 

"  Ainsi  Ton  peut  assurer  que,  parmi  ses  productions,  la  nature  n'a 
reellement  forme  ni  classes,  ni  ordres,  ni  families,  ni  especes  con- 
stantes,  mais  seulement  des  individus  qui  se  succedent  les  uns  aux 
autres,  et  qui  ressemblent  h  ceux  qui  les  ont  produits.  Or  ces 
individus  appartiennent  h.  des  races  infiniment  diversifiees,  qui 
se  nuancent  sous  toutes  les  formes  et  dans  tons  les  degres 
d'organisation,  et  qui  chacune  se  conservent  sans  mutation  tant 
qu'aucune  cause  de  changement  n'agit  sur  elles."     I.  22. 

"  La  supposition  presque  generalment  admise,  que  les  corps 
vivans'  constituent  des  especes  constamment  distinctes  par  des 
caracteres  invariables,  et  que  I'existence  de  ces  especes  est  aussi 
ancienne  que  celle  de  la  nature  meme,  fut  etablie  dans  un  temps 
ou  Ton  n'avait  pas  suffisament  observd,  et  ou  les  sciences  naturelles 
^taient  k  peu  pres  nulles.  Elle  est  tous  les  jours  dementie  aux 
yeux  de  ceux  qui  ont  beaucoup  vu  et  qui  ont  longtemps  suivi  la 
nature."    I.  54. 

"  Les  especes  n'ont  reellement  qu'une  Constance  relative  k  la 
dureedes  circonstances  dans  lesquelles  se  sont  trouve's  les  indi- 
vidus qui  les  reprdsentent."     I.  55. 


REFERENCES  AND   QUOTATIONS.  315 

**  — les  considerations,  et  nous  font  voir — 

"  I.  Que  tous  les  corps  organises  de  notre  globe  sont  de  vdrita- 
bles  productions  de  la  nature,  qu'elle  a  successivement  executccs 
k  la  suite  de  beaucoup  de  temps. 

"  2.  Que  dans  sa  marche  la  nature  a  commencd  et  recommence 
encore  tous  les  jours,  par  former  les  corps  organises  les  plus 
simples,  et  qu'elle  ne  forme  directement  que  ceux-lk,  c'est  k  dire 
que  ses  premieres  dbauches  de  I'organisation,  qu'on  a  designees 
par  I'expression  de  generations  spontandes. 

"  3.  Que  les  premieres  ebauches  de  I'animal  et  du  vegetal  dtant 
formees  dans  les  lieux  et  les  circonstances  convenables,  les  facultes 
d'une  vie  commengante  et  d*un  mouvement  organique  etabli  ont 
necessairement  developpe  peu  k  peu  les  organes,  et  qu'avec  le 
temps  elles  les  ont  diversifies  ainsi  que  les  parties. 

"  4.  Que  la  faculte  d'accroissement  dans  chaque  portion  du  corps 
organist  etait  inherente  aux  premiers  effets  de  la  vie  ;  elle  a  donne 
lieu  aux  differens  modes  de  la  multiplication  et  de  regenerations 
des  individus  ;  et  que  par  la,  les  progres  acquis  dans  la  composi- 
tion de  I'organisation  et  dans  la  forme  et  la  diversite  des  parties 
ont  ete  conserves. 

"  5.  Qu'a  I'aide  d'un  temps  suffisant,  des  circonstances  qui  ont 
6t6  ndcessairement  favorables,  des  changemens  que  tous  les  points 
de  la  surface  du  globe  ont  successivement  subis  dans  leur  6ta.t,  en 
un  mot,  du  pouvoir  qu'ont  les  nouvelles  situations  et  les  nouvelles 
habitudes  pour  modifier  les  organes  des  corps  douds  de  la  vie, 
tous  ceux  qui  existent  maintenant  ont  6t6  insensiblement  formds 
tels  que  nous  les  voyons. 

"  6,  Enfin,  que  d'apres  un  ordre  semblable  de  choses,  les  corps 
vivants  ayant  dprouvd  chacun  des  changemens  plus  ou  moins 
grands  dans  Tetat  de  leur  organisation  et  de  leurs  parties,  ce  qu'on 
nomme  espece  parmi  eux  a  6t6  insensiblement  et  successivement 
ainsi  formd,  n'a  qu'une  Constance  relative  dans  son  dtat,  et  ne  pcut 
ainsi  etre  aussi  ancien  que  la  nature."    I.  65,  &c. 

"  La  progression  dans  la  composition  de  I'organisation  subit,  9k 
et  1^,  dans  la  sdrie  gdnerale  des  animaux,  des  anomalies  opdrdes  par 
influence  des  circonstances  d'habitation  et  par  celle  des  habitudes 
contractdes."     I.  135. 

"  Dans  tout  animal  qui  n'a  point  ddpassd  le  terme  de  ses 
developpemens,   I'emploi    plus    frequent  et  routing    d'un   organe 


3l6  THE  DOCTRINE  OF  DESCENT. 

quelconque  fortifie  peu  h.  peu  cet  organe,  le  developpe,  I'agrandit, 
et  lui  donne  une  puissance  proportionnde  k  la  duree  de  cet  emploi ; 
tandis  quel  e  defaut  constant  d'usage  de  tel  organe  Taffaiblit 
insensiblement,  le  ddt^riore,  diminue  progressivement  ses  facultds, 
et  finit  par  le  faire  disparaitre. 

"  Tout  ce  que  la  nature  a  fait  acquerir  ou  perdre  aux  individus 
par  I'influence  des  circonstances  ou  leur  race  se  trouve  depuis 
longtemps  exposde,  et  par  consequent,  par  I'influence  de  I'emploi 
predominant  de  tel  organe  ou  par  cclle  d'un  defaut  constant 
d'usage  de  telle  partie,  elle  le  conserve  par  generation  aux  nou- 
veaux  individus  qui  en  proviennent."     I.  235. 

"  La  volontd  dependant  toujours  d'un  jugcment  quelconque 
n'est  jamais  vdritablement  libre ;  car  le  jugcment  qui  y  donne 
lieu  est,  comme  le  quotient  d'une  operation  arithmdtique,  un 
rdsultat  ndcessaire  de  Tensemble  des  Elements  qui  I'ont  forme." 
1.342. 

"  Les  animaux  contractent,  pour  satisfaire  a  cesbesoins,  diverse? 
sortes  d'habitudes,  qui  se  transforment  en  eux  en  autant  de 
penchans,  auxquels  ils  ne  peuvent  rcsister  et  qu'ils  ne  peuvent 
changer  eux  memes.  De  Ik  I'origine  de  leurs  actions  habituelles 
et  de  leurs  inclinations  particulieres,  auxquelles  on  a  donnd  le  nom 
d'instinct.  Ce  penchant  des  animaux  k  la  conservation  des  habi- 
tudes et  au  renouvellement  des  actions  qui  en  proviennent,  dtant 
une  fois  acquis,  se  propage  ensuite  dans  les  individus,  par  la  voie 
de  la  reproduction  ou  de  la  generation,  qui  conserve  I'organisation 
et  la  disposition  des  parties  dans  leur  dtat  obtenu,  en  sorte  que  ce 
meme  penchant  existe  ddjk  dans  les  nouveaux  individus,  avant 
meme  qu'ils  I'aient  exercd."     I.  325. 

^^  The  acute  author  of  the  book,  "  Das  Unbewusste"  defines 
instinct  in  essentially  the  same  manner  as  Lamarck.  "  In  this 
sense  it  may  be  said  that  every  instinct  is  in  the  last  instance  by 
its  origin  an  acquired  habit,  and  the  proverb  that  *  habit  is 
second  nature '  thus  receives  the  unexpected  supplement  that  habit 
is  also  the  beginning  and  origin  of  the  first  nature,  i.e.,  of  instinct. 
For  it  is  always  habit,  i.e.,  the  frequent  repetition  of  the  same 
function,  which  so  firmly  impresses  the  mode  of  action,  however 
acquired,  upon  the  central  organs  of  the  nervous  system  that  the 
predisposition  thus  originated  becomes  transmissible."  p.  182. 

^^  The  highly  important  doctrine  which  Lvell  has  substantiated 


REFERENCES  AND  QUOTATIONS.  317 

^ith  his  rich  experience  is  also  distinctly  and  concisely  enunciated 
by  Lamarck  in  the  Philosophie  Zoologique : — 

"  Si  Ton  consid^re,  d'une  part,  que  dans  tout  ce  que  la  nature  op^re 
elle  ne  fait  rien  brusquement,  et  que  partout  elle  agit  avec  l/snteur 
et  par  degrds  successifs,  et  de  Tautre  part  que  les  causes  particu- 
iieres  ou  locales  des  desordres,  des  bouleversemens,  des  deplace- 
mens,  etc.,  peuvent  rendre  raison  de  tout  ce  que  Ton  observe  k  la 
surface  de  notre  globe,  et  sont  n^anmoins  assujetties  k  ses  lois  et 
k  sa  marche  gdn^rale,  on  reconnaitra  qu'il  n'est  nullement  necessaire 
de  supposer  qu'une  catastrophe  universelle  est  venue  culbuter  et 
detruire  une  grande  partie  des  operations  memes  de  lanature."  1. 80. 

2^  Principles  of  Geology. 

^®  In  1870,  as  well  as  in  1872,  the  majority  in  the  French 
Academy  bore  this  testimony  to  Darwin.  The  reiterated  proposal 
of  electing  him  a  member  was  certainly  not  rejected  until  such 
men  as  Milne-Edwards  and  Quatrefages  had  made  the  stand- 
point clear  to  the  scientific  judges. 

•'«  Origin  of  Species.     Fifth  Ed.  1872. 

The  other  works  cited  are,  "  The  Variation  of  Animals  and 
Plants  under  Domestication,"  1868  ;  "  The  Descent  of  Man  and 
Sexual  Selection,"  2nd  ed.,  1871;  ''Expression  of  the  Emotions  in 
Man  and  Animals,"  1872. 

^  Malthus  (1798)  investigated  the  conditions  of  the  increase  and 
decrease  of  human  population.  He  finds  that  the  rise  in  popula- 
tion is  necessarily  limited  by  the  means  of  subsistence,  and  that 
the  growth  increases  in  proportion  to  the  means  of  subsistence, 
setting  aside  some  special  impediments  easily  discovered.  These 
impediments,  which  always  keep  the  population  below  the  amount 
warranted  by  the  means  of  subsistence,  are  moral  restraint,  crime, 
and  misfortune.  Malthus  depicts  the  struggle  for  existence  without 
pronouncing  the  word  ;  he  demonstrates  that  the  dreams  of  a 
future  blissful  equality  of  all  mankind  on  the  earth  transformed 
into  a  vast  garden,  are  based  upon  delusions.  Each  individual 
must  much  rather  labour  indefatigably  to  ameliorate  his  position. 
By  the  experience  of  breeders  and  gardeners  he  knows  that 
animals  and  plants  may  be  improved  and  ennobled.  No  organic 
ennoblement  of  the  human  race  as  a  whole  is  perceptible,  nor  can 
the  human  race  be  ennobled  save  by  condemning  the  les  3  perfect 
individuals  to  celibacy. 


3l8  THE  DOCTRINE  OF  DESCENT. 

These,  and  similar  thoughts  in  the  work  of  Malthus,  first  sug- 
gested Darwin's  theory,  as  he  has  informed  us. 

*^  Variation  of  Animals  and  Plants.     I.  loo. 

^^  Two  treatises  by  A.  Kerner  are  also  very  instructive  with 
regard  to  the  question  of  species :  "  Gute  and  Schlechte  Arten." 
(Innsbruck,  1866.)  And  "  Die  Abhangigkeit  der  Pflanzenwelt  von 
Klima  und  Boden.  Ein  Beitrag  zur  Lehre  von  der  Enstehung  und 
Verbreitung  der  Arten,  gestiitzt  auf  die  Verwandtschaftsverhaltnisse, 
geographische  Verbreitung  und  Geschichte  der  Cytisusarten  aus 
dem  Stamme  Tubocytisus  D.C."  1869.  Kerner's  latest  work,  "  Die 
Schutzmittel  des  Pollens"  (Innsbruck,  1873)  is  likewise  an  admirable 
investigation  of  the  variability,  adaptation,  and  formation  of  species. 

*3  Origin  of  Species.     13th  ed.  p.  84. 

'''*  Origin  of  Species.     13th  ed.  p.  96. 

^  Origin  of  Species. 

^*  P.  7.  The  following  pages  contain  an  epitome  of  the  objec- 
tions offered  to  the  inadequacy  of  the  theory  of  selection. 

'•^  Moritz  Wagner,  Die  Darwin'sche  Theorie  und  das  Migrations- 
gesetz  der  Organismen,  1848. 

''*  Nageli,  Enstehung  und  Begriff  der  naturhistorischen  Art. 
(Sitzungsberichte  der  bairischen  Akademie  der  Wissenschaften), 
1865.  Nageli's  later  investigations  (Sitzungsberichte  der  mathe- 
matisch-physikalischen  Klasse  der  Miinchner  Akademie,  1872, 
p.  305)  confirm  the  doctrine  of  descent.  He  shows  that  the  grega- 
riousness  of  merely  allied  species  and  their  varieties  proves  more 
favourable  to  the  formation  of  species  than  isolation.  "  The  asso- 
ciated forms— of  certain  Alpine  plants— have,  as  it  were,  recipro- 
cally modified  one  another ;  they  exhibit,  to  express  myself  thus, 
a  specific  social  type,  which  is  difi'erent  in  each  asse7nblage,  and 
therefore  in  every  neighbourhood.  This  fact  incontrovertibly 
shows  that  the  forms  have  altered  since  they  were  associated. 

"  The  specific  social  type  consists  in  their  showing  a  notable 
accordance  in  certain  characteristics,  while  in  others  they  repre- 
sent extremes,  and  in  these  sometimes  exceed  all  their  congeners 
in  other  districts. 

"  From  these  facts  it  follows  undoubtedly  that  the  movement  in 
the  cenobitic  forms  ij.e.  living  together)  is  divergent.  For  extreme 
characteristics  are  developed  in  them,  whereas  the  eremitical 
forms  exhibit  a  medium  in  their  characteristics. 


REFERENCES  AND  QUOTATIONS.  319 

•*  Nagcli  proves  that  since  the  glacial  period  an  alteration 
has  taken  place  in  Alpine  plants,  and  the  manner  in  which  it 
occurred." 

^  J.  Broca,  L'Ordre  dcs  Primates.  Parallele  anatomique  de 
rhomme  and  des  singes,  1870. 

*^  Descent  of  Man,  p.  367. 

*'  At  the  time  at  which  we  write,  we  have  before  us,  unfortunately, 
only  the  incomplete  reports  of  the  daily  papers,  and  the  syllabus 
of  Professor  Max  Muller*s  "Three  Lectures  on  Mr.  Darwin's 
Philosophy  of  Language." 

^  ZoUner,  "  Ueber  die  Natur  der  Kometen"  (i  ed.  p.  305). 

^*  For  the  further  instruction  of  the  reader,  we  will  allow  another 
Philosopher  and  Naturalist  to  speak  respecting  the  primordial  com- 
mencement of  life,  to  our  apprehension  so  simply  accountable. 
The  hypothesis  of  origin  is  under  discussion.  In  the  critical 
examination  of  the  "  Philosophie  des  Unbewussten"  (7)  it  nms 
thus,  p.  22.  The  "  Philosophie  des  Unbewussten"  says,  p.  558  : 
"  It  is  probable  that  before  the  origin  of  the  first  organisms, 
organic  combinations  existed  which  (p.  556)  were  under  the  influ- 
ence of  a  damp  atmosphere,  abounding  in  carbonic  acid,  and  of  a 
higher  temperature,  light,  and  stronger  electric  influences.  If  these 
presuppositions  are  adopted,  and  the  consideration  added  that  if 
conditions  thus  favourable  to  primordial  generation  once  existed, 
which  they  must  have  done — they  probably  endured  during  con- 
siderable geological  periods — the  inference  is  in  truth  inevitable 
that  in  lapse  of  time  and  with  change  of  circumstances,  these 
organic  substances  aggregated  into  innumerable  combinations. 
Among  these  innumerable  modes  of  arrangement,  groupings  and 
combinations,  by  far  the  greater  portion  must  remain  at  the  grade 
of  inorga.nic /orm,  because  it  has  not  attained  the  needful  chemical 
composition  and  physical  properties  ;  a  very  much  smaller  portion 
of  the  results  produced  by  these  combinations  of  organic  materials 
might  perhaps  transitorily  approach  the  organic  form  or  even  actu- 
ally assume  it,  yet  without  possessing  the  constitution  necessary  to 
maintain  it  permanently ;  a  third  and  yet  smaller  portion  might 
perhaps  maintain  this  form  for  itself  in  the  exchange  of  material, 
about  as  long  as  the  approximate  duration  of  life  of  one  of  the 
most  primitive  of  the  present  Protists,  yet  lacked  those  properties 
which  preserve  the  species  by  division  and  reproduction  after  the 


520  THE   DOCTRINE  OF  DESCENT. 

natural  extinction  of  the  individual  ;  a  fourth  portion  might 
possess  the  properties  requisite  for  self-preservation  as  well  as  for 
the  preservation  of  the  genus,  yet  lacked  that  peculiar  tendency 
to  vary  (Philosophie  des  Unbewussten,  p.  591),  or  at  least  that  ten- 
dency to  vary  in  the  particular  direction  which  was  alone  capable 
of  leading  to  development  into  higher  forms ;  and  finally  a  fiftli 
portion  possessed  this  property  in  addition  to  the  others.  It  is  tlie 
progeny  of  the  fourth  and  fifth  classes  of  our  division  which  still 
populates  the  ocean  and  the  earth.*  From  which  species  of 
Monera  proceeded  the  advanced  development  of  the  Infusoria  ; 
whether  from  one  still  living  or  from  an  extinct  species  we  do  not 
know  as  yet ;  but  this  much  we  may  accept  as  certain,  that  the 
majority  of  the  Protists  that  we  still  know,  belong  to  that  fourth 
class  which  is  incapable  of  development.  The  persistence  of  the 
ephemeral  creations  of  our  second  and  third  classes  would  natu- 
rally be  secured  only  so  long  as  circumstances  continued  favour- 
able to  their  renewed  primordial  generation,  but  from  the  teleo- 
logical  standpoint  the  first  class  must  be  described  as  that  of  the 
completely  abortive  attempts  at  creation." 

These,  and  similar  more  or  less  interesting  fancies  to  which  we 
attribute  no  great  importance,  are  all  derived  from  Haeckcl's 
hypothesis  of  Autogony  ("  Generelle  Morphologic  der  Organis- 
men,"  179  seq.),  which  he  set  up  after  his  beautiful  discoveries  on 
the  simplest  organisms  now  existing — the  Monera  and  the  Protists. 
From  this  work  we  select  the  following  passage : — "  Doubtless  we 
must  imagine  the  act  of  autogony,  the  first  spontaneous  origin  of 
the  simplest  organisms,  to  be  quite  similar  to  the  act  of  crystal- 
lization. In  a  fluid,  holding  in  solution  the  chemical  elements 
composing  the  organism,  in  consequence  of  certain  movements  of 
the  various  elements  among  themselves,  certain  points  of  attraction 
are  formed,  at  which  the  atoms  of  the  organogenetic  elements 
(carbon,  oxygen,  hydrogen,  nitrogen)  enter  into  such  close  contact 
with  one  another  that  they  unite  in  the  formation  of  a  complex 
ternary  or  quaternary  molecule.  This  primary  group  of  atoms — 
perhaps  a  molecule  of  albumen — now  acts  like  the  analogous  crystal- 

*  It  is  a  simpler  and  more  probable  explanation  that  these  low  organisms 
continue  to  exist  because  there  is  room  for  them.  They  remain  in  spile  of 
difierentiation  and  in  con-equence  of  differentiation. 


REFERENCES  AND  QUOTATIONS.  32 1 

fine  molecule,  attracting  the  homogeneous  atoms  dissolved  in  the 
mother  wather ;  and  they  now  likewise  coalesce  in  the  formation  of 
similar  molecules.  The  albuminous  granule  thus  grows  and  trans- 
forms itself  into  a  homogeneous  organic  individual,  a  structureless 
moner  or  mass  of  plasma,  Kke  a  Protamseba,  &c.  Owing  to  the 
easy  divisibility  of  its  substance,  this  moner  constantly  tends  to- 
wards the  dissolution  of  its  recently  consohdated  individuality,  but 
when  the  constantly  preponderating  absorption  of  new  substance 
outweighs  the  tendency  to  dis-integration,  it  is  able  to  preserve  life 
by  the  exchange  of  material.  The  homogeneous  organic  individual, 
or  moner,  grows  by  means  of  imbibition  (nutrition)  only  until  the 
attractive  power  of  the  centre  no  longer  suffices  to  hold  the  whole 
mass  together.  In  consequence  of  the  preponderating  divergent 
movements  of  the  molecules  in  different  directions,  two  or  more 
centres  of  attraction  are  now  formed  in  the  homogeneous  plasma, 
which  henceforth  act  attractively  on  the  individual  substance  of  the 
simple  mould,  and  thereby  induce  its  fission,  or  partition,  into  two 
or  more  portions  (reproduction).  Each  part  forthwith  rounds  itself 
again  into  an  albuminous  individual,  or  mass  of  plasma,  and  the 
eternal  process  begins  again,  of  attraction  and  disruption  of  the 
molecules,  producing  the  phenomena  of  exchange  of  substance,  or 
nutrition,  and  reproduction." 

Relying  on  the  known  peculiarities  of  the  combinations  of 
carbon,  Haeckel  has  attributed  to  this  substance  the  most  im- 
portant part  in  his  representation  of  the  first  development  of  life 
and  the  phybiological  phenomena  of  the  lowest  organisms.  This 
is  the  "  carbon  theory  "  so  strongly  deprecated  by  his  antagonists. 
Minds  would  be  less  heated  on  the  subject  were  it  remembered 
that  a  refutation  of  this  "adventurous  attempt,"  as  Haeckel  terms 
it,  to  assist  the  idea  of  genesis,  would  not  change  a  hair  in  the 
compulsory  logical  necessity  of  acknowledging  the  evocation  of 
life  by  natural  means.  The  arguments  against  the  carbon  theory 
have  been  developed,  among  others,  by  Preyer,  "  Ueber  die  Erior- 
schung  des  Lebens  (Jena,  1873).  It  is  shown  that  carbon,  in  its 
present  terrestrial  conditions,  points  almost  exclusively  to  organic 
origin,  and,  as  yet,  no  source  of  carbon  has  been  demonstrated 
adequate  for  the  first  formation  of  living  bodies  on  the  earth. 
•*5A.  R.  Wallace,  The  Malay  Archipelago    (3rd   ed. :  London, 


322  THE   DOCTRINE  OF   DESCENT. 

1872),  and  Contributions  to  the  Theory  of  Natural  Selection  (3nd 
ed.:  1871). 

^"  "  The  hypothesis  of  Pangenesis,  as  applied  to  the  several  great 
classes  of  facts  just  discussed,  no  doubt  is  extremely  complex,  but 
so  assuredly  are  the  facts.  The  assumptions,  however,  on  which 
the  hypothesis  rests  cannot  be  considered  as  complex  in  any 
extreme  degree  ;  namely,  that  all  organic  units,  besides  having  the 
power,  as  is  generally  admitted,  of  growing  by  self-division,  throw 
off  free  and  minute  atoms  of  their  contents,  that  is,  gemmules. 
These  multiply,  and  aggregate  themselves  into  buds  and  the  sexual 
elements  ;  their  development  depends  on  their  union  with  other 
nascent  cells,  or  units,  and  they  are  capable  of  transmission  in  a 
dormant  state  to  successive  generations. 

"  In  a  highly  organised  and  complex  animal,  the  gemmules  thrown 
off  from  each  different  cell,  or  unit,  throughout  the  body  must  be 
inconceivably  numerous  and  minute.  Each  unit  of  each  part,  as  it 
changes  during  development — and  we  know  that  some  insects 
undergo,  at  least,  twenty  metamorphoses — must  throw  off  its 
gemmules.  All  organic  beings,  moreover,  include  many  dormant 
gemmules  derived  from  their  grand-parents  and  more  remote  pro- 
genitors. These  almost  infinitely  numerous  and  minute  gemmules 
must  be  included  in  each  bud,  ovule,  spermaozoon,  and  pollen  grain. 
Such  an  admission  will  be  declared  impossible,  but,  as  previously 
remarked,  number  and  size  are  only  relative  difficulties,  and  the 
eggs  or  seeds  produced  by  certain  animals  or  plants  are  so 
numerous  that  they  cannot  be  grasped  by  the  intellect."  Darwin, 
Variations  of  Anii.'^als  and  Plants,  II.  526. 

^^  A.  Rollet,  Ueber  die  Erscheinungsformen  des  Lebens  und  den 
beharrlichen  Zeugen  ihres  Zusammenhanges.  Almanach  der  kais. 
Akademie  der  Wissenschaften  (Wien,  1872). 

^*^  Darwin,  Variations  of  Animals  and  Plants,  I.  200. 

^'  V.  Graber,  Ueber  den  Tonapparat  der  Locustiden,  ein  Beitrag 
zum  Darwinismus.  Zeitschrift  fur  wissenschaftliche  Zoologie. 
Vol.  22. 

'■''^  Hermann  v.  Nathusius,  Vorstudien  fiir  Geschichte  und  Zuciit 
der  Hausthiere  zunachst  am  Schweineschadel,  1864. 

♦^>  lb.,  p.  108. 

*-  Descent  of  Man,  1.  412. 


REFERENCES  AND  QUOTATIONS.  323 

«3  Origin  of  Species.     13th  ed.,  p.  171. 

"  Lamarck  also  constructed  a  pedigree  at  the  end  of  his  "  Philo- 
sophie  Zoologique,"  in  which  he  disposes  of  the  greater  number 
of  classes,  while  he  attributes  to  the  remainder  another  point  of 
derivation.  He  thus  assumes  in  the  animal  kingdom  two  primordial 
forms  derived  from  primordial  generation.  His  scheme  is  as 
follows  : — 

TABLEAU 

Servant  a  montrer  I'origine  des  differents  animaux. 

Vers.  Infusoires. 

Polypes. 


Radiares. 


,..----"'  Insectes. 

- ' "  Arachnidps. 

Annelides.  Crustac^es. 

Cirripedes. 
MoUusques. 


Poissons. 
Reptiles. 


Oiseaux. 

Mammales  amphibiens. 

Monotremes.  •...  : 

■   ..  M.  cetacees. 

Mammales  onguicules.  : 

•  M.  ongul^s. 

A  comparison  of  this  pedigree  with  the  one  which  we  now  set  up 
is  extremely  interesting,  and  shows  the  progress  of  our  knowledge. 

22 


324  THE  DOCTRINE  OF  DESCENT. 

^^Zum  Streit  iiber  den  Darwinismus,  "Augsburger  Allgemeine 
Zeitung,"  1873,  No.  130. 

**  A  short  preliminary  communication  in  the  "  Revue  Scienti- 
fique"  (Paris,  1873).     No.  37. 

'^^Braun,  Ueber  die  Bedeutung  der  Entwickelung  in  der 
Naturgeschichte  (Berhn,  1872). 

"  The  vegetal  kingdom  shows  us — 

"  I.  Plants,  which  in  their  vegetative  development  of  the  germ, 
exhibit  a  sexual  generation,  mostly  in  a  thallus-like  form.  (Thallo- 
gens,  Bryophytes,  the  Thallophytes  of  the  authors,  and  Charas  and 
Mosses.) 

*'II.  Plants  in  which  the  first  generation  is  transitory,  and  only 
the  second  develops  into  the  vegetative,  leaf-forming  stem,  with- 
out, however,  advancing  to  the  stage  of  phenogams.  (Acrogens 
Cormophytes,  the  ferns,  &c.) 

"III.  Plants  in  which  metamorphosis  advances  as  far  as  the 
formation  of  a  blossom,  yet  without  reaching  the  final  formation, 
that  of  the  formation  of  the  carpel.  (Phenogams  without  real 
fruit,  gymnospermic  Anthophytes.) 

"  IV.  Plants  which  reach  the  final  and  highest  conclusion  of 
vegetable  development,  that  of  true  fructification.  (Angiospermic 
Anthophytes ;  Monocotyledons  and  Dicotyledons  as  secondary 
gradations.) 

^^  As  we  have  discussed  in  this  chapter  individual  development 
with  reference  to  historical  development,  we  must  also  notice  the 
strange  opposition  to  the  doctrine  of  descent  offered  by  KoUiker. 
He  has  laid  down  his  views  in  his  "  Monographic  der  Penna- 
tuliden,"  and,  in  a  separate  pamphlet,  bearing  the  title  of  "  Mor- 
phologic und  Entwickelungsgeschichte  des  Pennatuhdenstammes, 
nebst  allgemeine  Betrachtungen  zur  Descendenzlehre "  (Frank- 
furt, 1872).  Whereas  Darwinism  derives  the  continuity  and 
harmony  of  the  organic  world  from  variability,  natural  selection, 
heredity,  and  adaptation — in  short,  from  palpable,  visibly  efficacious 
causes — Kolliker  is  of  opinion  "that  the  same  general  formative 
laws  which  govern  inorganic  nature  hold  good  also  in  the  organic 
kingdom,  and  hence  a  common  pedigree  and  a  slow  transformation 
of  one  form  into  another  are  entirely  unnecessary  for  the  explana- 
tion and  comprehension  of  the  accordance  of  the  forms  and  series 


REFERENCES  AND  QUOTATIONS.  325 

)f  forms  of  the  animate  world"  (p.  3).  Except  decided  dualists,  no 
one  disputes  the  first  part  of  Kolliker's  thesis.  But  the  identifica- 
tion of  the  development  of  the  organic  individual,  excluding  the 
law  of  heredity,  with  the  simple  process  of  crystallization,  or  any 
other  operation  of  chemical  combination  repeating  itself  under 
given  conditions,  scarcely  needs  a  detailed  refutation.  Kolliker 
says,  and  tries  to  prove,  that  the  so-called  monophyletic  hypo- 
thesis, according  to  which  the  different  families  of  organisms  are 
derived  from  a  single  primordial  form,  has  to  struggle  with  insur- 
mountable difficulties;  that  the  hypothesis  of  descent  from  many 
families  (polyphyletic)  possesses  more  probability.  If  this  be 
admitted,  then — and  here  comes  a  bold  leap  of  the  imagination — 
the  adherent  of  the  polyphyletic  hypothesis  finds  himself  in  a 
position  to  attribute  different  pedigrees  and  primordial  forms  not 
only  to  the  higher  divisions,  but  even  to  their  genera,  and  to  assume 
their  independent  origin.  Nay,  it  even  seems  credible  that  the 
self-same  species  may  appear  in  different  pedigrees ;  as  by  the 
incontrovertible  supposition  of  general  laws  of  formation,  it  cannot 
be  seen  why  like  primary  shapes  should  not,  under  certain  circum- 
stances, be  able  to  lead  to  like  final  forms  (see  p.  21).  Nay,  this 
hypothesis  does  more,  for  "  even  if  individuals  of  the  same  species 
occupy  remote  localities,  as,  for  instance,  Pennatula  phosphorea, 
Funiculina  quadrangularis,  Renilla  reniformis,  &c.,  it  is  surely  more 
fitting  to  assume  their  independent  origin."  Kolliker's  polyphyletic 
hypothesis  put  an  end  to  all  difficulties,  and,  among  others,  it  ex- 
plains the  so-called  "representative  forms"  to  be  mentioned  in  our 
tenth  chapter;  for,  from  "this  standpoint,  it  is  credible  that  these 
forms  are  not  genetically  connected,  but  belong  to  different  pedi- 
grees" (p.  23).  And  all  this,  and  much  more,  is  supposed  to  be 
conceivable,  because  the  world  of  organisms,  in  its  consecutive 
development,  follows  intrinsic  causes  or  definite  laws  of  formation, 
"  laws  which,  in  a  perfectly  definite  manner,  urge  on  the  organisms 
to  constantly  higher  development."  At  the  same  time,  Kolliker 
deliberates  (p.  38)  whether,  just  as  here  germs  and  buds,  so  also 
ft  ee  existing  youthful  forms  of  animals  did  not  possess  the  power 
of  striking  out  a  development  different  from  the  typical  one,  which 
freedom  must  be  severely  mulcted  by  the  law  of  development, 
which  can  and  must  create  individuals  of  the  same  species  at  the 


326  THE   DOCTRINE   OF   DESCENT. 

opposite  poles.  Kolliker  (p.  44)  thus  sums  up  his  fundamental 
view — "  that  in  and  with  the  first  origin  of  organic  matter  and  of 
organisms,  the  whole  plan  of  development,  the  collective  series  of 
possibihties,  were  also  potentially  given,  but  that  various  external 
impulses  operated  determinatively  on  individual  developments,  and 
impressed  a  definite  stamp  upon  them."  Notwithstanding  the 
scientific  dress,  dualism  is  here  complete  ;  whereas.  Physics  and 
Chemistry  make  their  laws,  applying  to  inorganic  as  well  as  to 
organic  nature,  comprehensible  in  their  form,  purport,  and  effects, 
Kolliker  knows  nothing  of  the  constitution  of  his  laws.  The 
doctrine  of  natural  selection  allows  us  to  recognize  the  causes  and 
effects  of  heredity  and  adaptation,  and  establishes  the  phenomenal 
series  under  the  form  of  laws.  But  laws  which  are  founded  only 
on  a  plan  which  is  to  be  carried  out  prospectively  and  in  subser- 
vience to  this  dower  of  imperfect  organisms,  are  ignored  by  natural 
science. 

^  Ueber  die  Herkunft  unserer  Thierwelt.  Einezoo-geographische 
Skizze  von  L.  Riitimeyer  (Basel,  1867).  We  have  made  copious 
use  in  our  text  of  this  extremely  instructive  writing. 

'"  A.  R.  Wallace,  Malay  Archipelago.  P.  10,  &c.  See  also  his 
remarkable  and  comprehensive  work  on  the  Geographical  Distri- 
bution of  Animals. 

'^  G.  Koch,  Die  indo-australische  Lepidopteren-Fauna  in  ihren 
Zusamnenhang  mit  den  drei  Hauptfaunen  der  Erde.  (i  Ed.,  Ber- 
lin, 1873.) 

'^  Peschl,  Neue  Probleme  der  vergleichende  Erdkunde,  1870. 

'^  Unless  we  connect  the  Dinotherium  with  Mastodon  and  Ele- 
phas.  Between  the  pliocene  Mastodon  Borsoni  and  the  Elephas 
primigenius,  twenty  species  are  interposed,  among  which  are  our 
still  living  species,  the  Indian  and  African  elephants.  The  limits 
of  the  two  genera  are  hereby  entirely  obhterated.  According  to 
other  statements,  the  Elephas  primigenius  (the  mammoth)  falls 
into  at  least  four  geographical  varieties,  which  join  on  to  the 
American  species.  A  dwarf  species  of  elephant  is  found  in  the 
caves  of  Malta,  which  in  dentition  attaches  itself  to  the  African 
species. 

''*  Joh.  Schmidt,  The  Relationships  of  the  Indo-Germanic  Lan- 
guages.    1872. 

'^  Various  antagonists  of  the  doctrine  of  descent  have  vented 
their  moral  dismay  in  the  most  poignant  expressions,  precluding 


REFERENCES  AND   QUOTATIONS.  327 

any  scientific  discussion,  on  finding  that  the  pedigree  of  the  Verte- 
brata,  and  therewith  of  man,  is  actually  traced  beyond  the  verle- 
brated  animals  to  so  low  a  being  as  the  Ascidians.  It  is  otherwise 
with  the  critics  of  Kowalewsky's  and  Kupffer's  observations,  who 
acknowledge  the  facts,  but  think  themselves  obliged  to  differ  in 
their  interpretation.  One  of  these  is  A.  Giard,  in  his  work  on 
the  "  Embryogcnie  des  Ascidiens.''  (Archive  de  Zoologie  experi- 
mentale,  Paris,  1872.)  The  pupil  of  Lacaze  Duthiers  says  : — "  La 
chorde  et  I'appendice  caudale  sont  chez  la  larve  Ascidienne  des 
organes  de  locomotion  d'un  importance  assez  secondaire  malgrd 
leur  gendralite,  pour  qu^on  les  vote  disparaitre  presqtie  entiereme7it 
dans  le  geny-e  Molgula,  ou  ils  sont  devenus  inutiles  par  suite  des 
mceurs  de  I'animal  adulte  :  I'homologie  entre  cette  chorde  dorsale 
et  celle  des  vertebres  n'est  done  qu'une  homologie  d^ adaptatio7i 
d^terminde  k  remplir  I'iodentiti^  des  fonctions,  et  n'indique  pas  de 
rapports  de  parente  immediate  entre  les  vert^brds  et  les  Ascidiens." 
The  author  thus  denies  the  consanguinity  of  the  vertebrate  animals 
and  Ascidians,  and  traces  back  to  adaptation  the  resemblance 
approaching  identity  occurring  in  the  organs  of  the  two.  The 
inferences  in  these  few  sentences  appear  to  us  utterly  at  fault. 
The  circumstance  that  in  Molgula,  and  many  other  Testacea,  de- 
velopment takes  a  narrower  course,  makes  as  little  alteration  in  the 
importance  of  the  facts  as,  for  instance,  the  Nauplius  development 
of  the  Peneus  observed  by  Fritz  IVIiiller,  or  the  Navicula  of  the 
Molluscs,  is  prejudiced  by  the  fact  that  the  other  Decapods  have 
forfeited  the  Nauplius  phase,  or  the  laandsnails  the  navicula  phase. 
But  it  is  simply  incomprehensible  in  what  the  identity  of  functions 
is  to  consist  which  in  the  Vertebrata  was  capable  of  producing 
the  notochord,  with,  it  is  particularly  to  be  remarked,  the  spinal 
cord  (which  M.  Giard  entirely  forgets) ;  and,  in  the  other  case, 
the  "  homologie  d'adaptation."  We,  on  the  contrary-,  see  these 
organs  performing  different  functions,  because  in  the  one  they 
remain  of  fundamental  importance  through  life,  and  not  in  the 
other.  Thus  we  conversely  lay  the  stress  on  the  morphological 
identity  accompanjing  functional  difference.  M.  Giard  adduces 
no  facts. 

^^  T.  H.   Huxley,  Manual  of  the  Anatomy  of  the  Vertebrated 
fVnimals.     German  Ed. 


328  THE   DOCTRINE   OF  DESCENT. 

^7  March,  American  Journal  of   Sciences   and  Arts,   February, 

1873. 

'**  Eckermann,  Gesprache  mit  Goethe.  II.  152. 

^^  Rousseau,  Emile  (CEuvres,  Paris,  1820,  IX.  17).  "  Nous  n'avons 
point  la  mesure  de  cette  machine  immense ;  nous  n'en  pouvons 
calculer  les  rapports  ;  nous  n'en  connaissons  ni  les  premieres  lois, 
ni  la  cause  finale  ;  nous  nous  ignorons  nous-memes  ;  nous  ne  con- 
naissons ni  notre  nature,  ni  notre  principe  actif." 

^*  Metamorphose  der  Thiere. 

«i  R.  Valdek  in  the  "  Presse,"  1865,  No.  327. 

8^  Huxley,  Man's  Place  in  Nature,  1863.  Manual  of  the  Anatomy 
of  the  Vertebrated  Animals. 

^3  Broca,  L'Ordre  des  Primates.  Parallele  anatomique  des 
I'Homme  et  des  Singes.  (Paris,  1870.) 

^■^  Waitz,  Anthropologie  der  Naturvolker,  6  thl.,  p.  796.  Bear- 
beitet  von  Gerland. 

^  Do.  p.  708. 

»"  "  Augsburger  Allgemeine  Zeitung,"  1873,  Nos.  92-94.    Beilage. 

^^  I  heard  the  lectures  delivered  at  Strasburg  by  this  scholar, 
"  Ueber  die  Resultate  der  Sprachswissenschaft,"  with  great  inteit^st 
and  advantage. 

'^  L.  Geiger,  Der  Ursprung  der  Sprache,  1869,  p.  37. 

"^  Steinthal,  Der  Ursprung  der  Sprache,  1851. 

'•^  Fr.  •Miiller,  Allgemeine  Ethnographic.     We.ii.,  1873. 


INDEX. 


Agassiz,  L.  ii,  So.  86,  223. 

Alca  impsnnis,  186. 
Amblystoma,  210. 
Ammonites,  71,  74,  97' 
Aniniotes,  250. 
Amphibians,  209.  258,  264. 
Amphioxus.     See  Lancelel. 
Anchitherium,  242,  273. 
Ancyloceras,  216, 
Anguis,  185. 
Annelids,  32,  198. 
Annulosa,  260. 
Anoplotheridoe,  274. 
Anteater,  246, 
Antelopes,  273,  277. 
Apes.  280,  288, 
Araclmida,  33. 
Archaeopteryx,  72,  265. 
Archaeosauros,  83. 
Archegosauros,  258. 
Armadillos,  228,  246. 
Articulata,  32,  53,  72,  20T,  219. 
Ascarides,  206. 
Ascidians,  36,  219,  252. 
Axolotl,  209, 


B.ier,  C.  E.   von,   48,    191, 

219,  293. 
Balenidos,  280. 
Barraude,  11. 


157.    201, 


Bathybius.  26^ 
Batracliians.  72.  258.  264. 
Bats,  228,  246  269. 
Bavey,  212. 
Bears,  243. 

Beaumont,  Elie  de,  i;^). 
Beavers,  247. 
Bees  28,  47, 
Beetles,  185. 
Belemnites,  74. 
Beneden,  Van,  209. 
Birds,  227  232,  250,  265 
Bison,  277. 
Blastoids,  jj, 
Bleek,  304. 
Bos,  277. 
Bourguignat,  224, 
Brachiopoda,  70. 
Braun,  193,  22a 
Brehm,  182,  267. 
Broca,  Prof.  160,  187. 
Briicke,  26. 
Bruta,  237,  271. 
Bubalos,  277. 
Buffaloes,  244,  247. 
Buffon,  5. 
Butterflies,  227. 

Cachelots,  2Sa 
Camels,  223. 


330 


INDEX. 


Camper,  P.  iot,  119. 

Campsognathus,  264. 

Canidae,  278. 

Carnivora,  241,  273,  278. 

Carpenter,  Dr.  64,  93. 

Cassowaries,  237. 

Cassidulidae,  77. 

Cats,  100,  170,  234. 

Cecidomyia,  47. 

Cephalopoda,  70,  154,  cor. 

Ceratoda,  258. 

Cercaria,  46. 

Ceroxylus  laceratus,  181. 

Cestoda,  205. 

Cetacea,  238,  273,  279. 

Chalina,  154. 

Chalinula,  154. 

Cheiroptera,  280. 

Chelonia,  263. 

Chimpanzee,  288, 

Chirotes,  185, 

Cidaridae,  'j'j. 

Cirripedes,  207. 

Civets,  234. 

Cladonema  Radiatum,  42,  202. 

Clymenia,  71. 

Clypeastroe,  80, 

Coccoliths,  26. 

Cockleshell,  199. 

Coecilia,  259. 

Coelenterata,  31,  2i3, 

Coenopithicus,  245. 

Coleoptera,  184. 

Comatula,  80,  197. 

Conchifera,  71. 

Copepoda,  207. 

Corals,  42. 

Crabs,  150,  153,  207,  210,  238. 

Credner,  64. 

Crinoid,  56,  "jS. 

Crocodiles,  75,  260  263- 

Crossopterygii,  258. 

Ctenon)ys,  184. 

Curtius,  G.  304. 


Cuscus,  234. 
Cuttlefish,  II. 
Cuvier,  30,  85. 
Cyclostomi,  256. 
Cytisus,  146. 

Darwin,  131,  184,  248 
Deciduata,  272. 
Deer,  234,  246,  275. 
Delphinoidae,  279. 
Dentalium  Teredo,  200. 
Desor,  76. 
Dicynodonta,  260. 
Didelphidae,  245. 
Dinosauria,  261. 
Dinotherium,  295. 
Dipnoi,  37,  256,  258. 
Distoma,  46,  206. 
Dodo,  186. 
Dogs,  99,  138. 
Dubois-Reymond,  15,  iio. 
Duck-mole,  237. 
Dujardin,  42. 
Dumeril,  A.  209. 


Earl,  G.  Windsor,  23a 

Echidna,  270. 

Echinae,  'j6,  80. 

Echinoconidoe,  77. 

Echinodermata,  31,  76. 

Edentata,  79,  237,  246,  269,  271. 

Elasmobranchii,  256. 

Elephants,  80,  231,  242.  247,  269,  si'o 

Enaliosaurians,  74,  238,  260. 

Endocyclica,  tj. 

Eozoon,  68. 

Ephippigera  vitium,  17a. 

Eucladiajohnsoni,  76. 

Feather  stars,  76. 
Fick.  A.  18. 
Fisk,  260,  264. 


INDEX, 


33 


Foraminifeni,  93, 
Forster,  G.  loi 
Fowls,  135. 
Frogs,  258. 
I'"urbringer,  1S5. 

Ganoids,  71.  256. 
Gargo!.  44. 
Gasteropoda,  70. 
Gastrula,  51,  218,  i-j* 
Gegenbauer,  74,  23^. 
Gerland,  300. 
Gibbon,  289. 
Giraffes,  277. 
Goats,  277. 
Goethe,  100. 
Gorilla,  288. 
Graber,  Von,  171. 
Graminivora,  2-,o. 
Graptolites,  69. 
Gratiolet,  291. 
Guinea-pig,   100. 

Haeckel,  40,  89,  178,  198,  218,  2-a 
Heer,  238. 

Heliadotberium,  277. 
Helliconidae,  179. 
Herder,  4. 
Hilgendorf,  96. 
Hipparion,  273. 
Hippopotamus,  242,  275. 
Holothuria,  78,  197,  217. 
Honeysuckers,  233. 
Horses,  81,  170,  225,  242,  273,  295. 
Humboldt,  W.  von,  4,  222. 
Huxley,  257,  264,  289,  307. 
Hydractinea  carnea,  203. 
Hydra  tuba,  178. 
Hydrophilus  piceus,  53. 
Hyaenas,  243,  278. 
Hylodon  Martinicensis,  217^ 
Hypsilophodoe,  265. 
Hyrax,  269,  277. 


Ichthyomis  dispar,  267. 
Ichthyosauria,  74,  260. 
Infiata,  216. 
Infusoria,  269,  280. 
Insecta,  32. 
Insectivora,  269,  280. 

Kangaroos,  233. 
Kerner,  146. 
Korte,  Dr.  117. 
Kovvalewsky,  199,  219,  251. 

Labyrinthodonta,  72. 
Lacertilia,  262. 
Lama,  223,  245. 
Lamarck,  85,  124,  148. 
Lamellibranchiata,  199. 
Lancelet,  36,  150,  219,  251. 
Laplace,  15. 
Leibnitz,  2. 
Lemurs,  269,  280. 
Lepidosirens,  37,  238,  258, 
Leptalidae,  180. 
Leptoiherium,  245. 
Linnaeus,  5,  84- 
Lions,  223. 
Lizards,  185,  261. 
Locke,  303. 
Lories,  233. 
Luca,  289. 
Luthardt,  12. 
LyeU,  Sir  C.  128. 

Machairodus,  242. 
Macrauchenidae,  273. 
Madrepores,  42. 

Mammals,  73,  240,  250,  264  269,  vjj. 
Mammoths,  79,  244,  247. 
Man,  Tii,  201,  269,  288. 
Mantidae,  181. 
vlarsh,  267. 
Marsipobranchii,  256. 
Marsupial  frog,  214- 
Marsupials,  73,  75,  228,  238,  250,  2O9. 


332 


INDEX. 


Martens,  241,  247, 

Mastodon,  8r. 

Maupertuis,  4. 

Maury,  227. 

Mayer,  Ernst,  118. 

Med  usee,  31,  202,  210,  218. 

^tegalonyx  Jeifcrsoni,  246. 

Mollusca,  33,  199. 

Monera,  27. 

Monkeys,  79,  234,  269, — 5<r^  Apes. 

Monotremata,  269. 

MUIler,  Friedrich,  305. 

MliUer,  H.  299. 

Miiller,  Johannes,  279. 

Milller,  Max,  161,  208,  238,  303. 

Musk  animals,  242. 

Mylodon  Harlemi,  246. 

Myriapoda,  32. 

Myxine,  258, 

Nageli,  160,  193. 
Nathusius,  H.  von,  175,  178. 
Naumayr,  97. 
Nauplius,  207,  2ro, 
Navicula,  199. 
Nematoids,  206. 

Ok  en,  105. 

Ophiura,  198. 

Opossums,  233,  245, 

Orang,  288. 

Omiscelidae,  260. 

Ornithorhyncus,  37,  237,  27a 

Orthoptera,  171. 

Ostrich,  237. 

Ouistitis,  291. 

Ovibos,  277. 

Owen,  R.  121,  193,  390^ 

Oxen,  247,  275. 

Oysters,  201. 

Pachyderms,  79,  240,  242. 
Palseochoeridoe,  244. 


Palceoniscus,  71. 

Pala-'otheridce,  273, 

Paludina,  200. 

Pander,  219. 

Pavians,  289. 

Peneus,  208. 

Petromyzon,  2561, 

Phasmidce,  181. 

Physeteridas,  280. 

Pigs,  175,  178,  242,  244.  275. 

Pigeons,  133,  170,  177. 

Pinnipedas,  278. 

Placoids,  71, 

Planorbis  multiformis,  96. 

Platehnintha  Suctoria,  205, 

Platypus,  233. 

Plesiosaurians,  74,  260. 

Pleuronectidoe,  181. 

Polecats,  241. 

Polistes  Gallica,  47. 

Polypes,  28,  30,  174,  203,  2i8. 

Polypterus,  258. 

Primates,  308. 

Proboscidae,  273. 

Protamoeba,  26,  4a 

Proterosaurus,  73. 

Proteus,  259, 

Protopterus,  23S,  258. 

Pseudopus,  185. 

Pterodactyls,  75,  250,  253,  =5& 

Pterotrachia,  199. 

Pulmo-gasteropoda,  224- 

Puma,  223. 


Quadrumana,  245. 


Radiata,  31. 
Rathke,  55. 
Regularae,  'jj. 
Reniera,  94,  154, 
Reptiles,  250,  264, 
Rhabdoliths,  35. 


INDEX. 


333 


Rhinoceros,  231,  242.  247.  273*  3io- 
Rhizopoda,  207. 
Rodents,  246,  269,  278,  280. 
Rollet.  26,  168. 
Rousseau,  J.  J.  4' 
Ruminants,  79,  240,  277. 
Rutimeyer,  81,  222,  227,  236,  257,  273. 
277. 


Sagitta,  37.  216,  219. 
Sahuis,  289. 
Saint  Hilaire,  E.  G.  85. 
Salamanders,  209,  211,  258. 
Salmon,  239. 
Sauria,  260. 
Sauropsida,  264. 
Scaphites,  76. 
Schleicher,  304- 
Schmidt,  Johannes.  249. 
Schulze,  Max,  154. 
Sea-cows,  277. 
Sea-cucumbers,  77,  197. 
Seals,  269. 
Sea-snails,  198. 
Sea-urchins,  76,  197. 
Semper,  42. 
Serpents,  260. 
Sheep,  136,  244,  277. 
Shrimp,  208. 
Siebold,  Von,  47. 
Sirens,  238,  269,  277. 
Sivatherium,  277. 
Sloths,  228,  246. 
Snails,  224. 
Snakes,  185. 
Spatangoe,  77,  80. 
Spongiadae,  30,  93,  218. 
Squalodon,  279. 
Starfish,  76,  197. 
Stauridium,  42,  20a. 
Stein,  41. 
Steinthal,  304. 


Stone-lilies,  j6,  8>. 
Strauss,  D.  F.  30a. 
Sturgeons,  238. 
Suctoria,  206. 
Suidae,  276. 
Surinam  toad,  21a. 
Siissmilch,  4. 


Tapeworm,  43,  205. 
Tapirs,  231,  242,  27^. 
Tedania,  94. 
Teleostei,  256. 
Tellina,  96. 
Termites,  178. 
Tesselloe,  77. 
Testacea,  250,  252. 
Tetrabranchiata,  199. 
Thompson,  W.  64. 
Threadworms,  206. 

Thrushes,  234. 

Tiger,  241. 

Toenia  solium,  44. 

Tortoises,  75,  238,  2G0,  263. 

Tragulidae,  275. 

Trematoda,  205. 

Trilobites,  69. 

Tritons,  209,  259. 

Trogons,  234. 

Tuco-tuco,  184. 

Turbellaria,  37,  45.  205. 

Turrilites,  76. 


Unger,  F.  72. 

Ungulates,  240,  242,  269,  273,  277. 

Ursidae,  278. 


Verany,  182. 

Vermes,  32,  201. 

Vertebrata,  33,  154.  '^S.  25°.  '*^^' 

Viverridae,  241 ;  278, 


i 


334 

Wagner,  M.  158,  3DC 
Waitz,  3CX5. 
Wallace,  164,  230. 
Wall  uses,  279. 
Watson,  H.  C.  151. 
Werner,  129. 
Whales,  269.  23o. 
Wolves,  100. 
Wombats,  253. 


INDEX. 


Woodpeckers,  23.J. 
Worms,  205. 
Wiirtenberger,  97,  a  13. 


Zeuglodon,  279. 
Zoea,  208. 
ZoUner,  21,  i6^*. 


THE  UNIVERSITY  LIBRARY 

UNIVERSITY  OF  CALIFORNIA,  SANTA  CRUZ 

SCIENCE  LIBRARY 

This  book  is  due  on  the  last  DATE  stamped  below. 
To  renew  by  phone,  call  429-2050 


3077i-9,'72  (Q4585s8 )  — 3A-1 


QH367.S35  Sci 


3  2106  00251    9210 


J 


^^^, 


*%J 


^^^^^^il^'l^ 


-\-:^-M" 


